diff --git a/src-tauri/src/models/connection.rs b/src-tauri/src/models/connection.rs
index 2bc656a..03c0d47 100644
--- a/src-tauri/src/models/connection.rs
+++ b/src-tauri/src/models/connection.rs
@@ -11,6 +11,7 @@ pub struct ConnectionConfig {
     pub database: String,
     pub ssl_mode: Option<String>,
     pub color: Option<String>,
+    pub environment: Option<String>,
 }
 
 impl ConnectionConfig {
diff --git a/src/components/connections/ConnectionDialog.tsx b/src/components/connections/ConnectionDialog.tsx
index 0a9d5b1..220971c 100644
--- a/src/components/connections/ConnectionDialog.tsx
+++ b/src/components/connections/ConnectionDialog.tsx
@@ -18,6 +18,7 @@ import {
 import { useSaveConnection, useTestConnection } from "@/hooks/use-connections";
 import { toast } from "sonner";
 import type { ConnectionConfig } from "@/types";
+import { ENVIRONMENTS } from "@/lib/environment";
 import { Loader2, X } from "lucide-react";
 
 const CONNECTION_COLORS = [
@@ -47,6 +48,7 @@ const emptyConfig: ConnectionConfig = {
   database: "postgres",
   ssl_mode: "prefer",
   color: undefined,
+  environment: undefined,
 };
 
 export function ConnectionDialog({ open, onOpenChange, connection }: Props) {
@@ -184,6 +186,38 @@ export function ConnectionDialog({ open, onOpenChange, connection }: Props) {
               </SelectContent>
             </Select>
           </div>
+          <div className="grid grid-cols-4 items-center gap-3">
+            <label className="text-right text-sm text-muted-foreground">
+              Environment
+            </label>
+            <Select
+              value={form.environment ?? "__none__"}
+              onValueChange={(v) =>
+                setForm((f) => ({
+                  ...f,
+                  environment: v === "__none__" ? undefined : v,
+                }))
+              }
+            >
+              <SelectTrigger className="col-span-3">
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="__none__">None</SelectItem>
+                {ENVIRONMENTS.map((env) => (
+                  <SelectItem key={env.value} value={env.value}>
+                    <div className="flex items-center gap-2">
+                      <span
+                        className="h-2 w-2 rounded-full"
+                        style={{ backgroundColor: env.color }}
+                      />
+                      {env.label}
+                    </div>
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
           <div className="grid grid-cols-4 items-center gap-3">
             <label className="text-right text-sm text-muted-foreground">
               Color
diff --git a/src/components/connections/ConnectionList.tsx b/src/components/connections/ConnectionList.tsx
index 95b9b3b..48ebdaa 100644
--- a/src/components/connections/ConnectionList.tsx
+++ b/src/components/connections/ConnectionList.tsx
@@ -23,6 +23,8 @@ import {
   Loader2,
 } from "lucide-react";
 import type { ConnectionConfig } from "@/types";
+import { EnvironmentBadge } from "@/components/connections/EnvironmentBadge";
+import { ENVIRONMENTS } from "@/lib/environment";
 
 interface Props {
   open: boolean;
@@ -80,87 +82,127 @@ export function ConnectionList({ open, onOpenChange, onEdit, onNew }: Props) {
         </SheetHeader>
         <div className="overflow-y-auto overflow-x-hidden" style={{ height: "calc(100vh - 80px)" }}>
           <div className="space-y-2 px-4 pb-4">
-            {connections?.map((conn) => {
-              const isConnected = connectedIds.has(conn.id);
-              const isActive = activeConnectionId === conn.id;
+            {(() => {
+              if (!connections || connections.length === 0) {
+                return (
+                  <div className="py-8 text-center text-sm text-muted-foreground">
+                    No saved connections.
+                    <br />
+                    Click "New" to add one.
+                  </div>
+                );
+              }
 
-              return (
-                <div
-                  key={conn.id}
-                  className={`flex items-center gap-2 overflow-hidden rounded-md border p-3 ${
-                    isActive ? "border-primary bg-accent" : ""
-                  }`}
-                >
-                  {conn.color ? (
-                    <span
-                      className="h-4 w-4 shrink-0 rounded-full"
-                      style={{ backgroundColor: conn.color }}
-                    />
-                  ) : (
-                    <Database className="h-4 w-4 shrink-0 text-muted-foreground" />
-                  )}
-                  <div className="min-w-0 flex-1">
-                    <div className="truncate text-sm font-medium">
-                      {conn.name}
-                    </div>
-                    <div className="truncate text-xs text-muted-foreground">
-                      {conn.host}:{conn.port}/{conn.database}
-                    </div>
-                  </div>
-                  <div className="flex shrink-0 items-center gap-0.5">
-                    {isConnected ? (
-                      <Button
-                        size="icon"
-                        variant="ghost"
-                        className="h-7 w-7"
-                        onClick={() => handleDisconnect(conn.id)}
-                        disabled={disconnectMutation.isPending}
-                      >
-                        <Unplug className="h-3.5 w-3.5" />
-                      </Button>
-                    ) : (
-                      <Button
-                        size="icon"
-                        variant="ghost"
-                        className="h-7 w-7"
-                        onClick={() => handleConnect(conn)}
-                        disabled={connectMutation.isPending}
-                      >
-                        {connectMutation.isPending ? (
-                          <Loader2 className="h-3.5 w-3.5 animate-spin" />
+              const envOrder = ["prod", "stage", "dev", "local"] as const;
+              const grouped = new Map<string, ConnectionConfig[]>();
+              for (const conn of connections) {
+                const key = conn.environment ?? "";
+                const list = grouped.get(key);
+                if (list) list.push(conn);
+                else grouped.set(key, [conn]);
+              }
+              const sortedKeys = [...grouped.keys()].sort((a, b) => {
+                const ai = a ? envOrder.indexOf(a as typeof envOrder[number]) : envOrder.length;
+                const bi = b ? envOrder.indexOf(b as typeof envOrder[number]) : envOrder.length;
+                return (ai === -1 ? envOrder.length : ai) - (bi === -1 ? envOrder.length : bi);
+              });
+              const showHeaders = sortedKeys.length > 1;
+
+              return sortedKeys.map((key) => {
+                const group = grouped.get(key)!;
+                const envDef = ENVIRONMENTS.find((e) => e.value === key);
+                return (
+                  <div key={key || "__none__"}>
+                    {showHeaders && (
+                      <div className="mb-1 mt-2 flex items-center gap-1.5 text-[11px] font-semibold uppercase text-muted-foreground first:mt-0">
+                        {envDef ? (
+                          <>
+                            <span className="h-2 w-2 rounded-full" style={{ backgroundColor: envDef.color }} />
+                            {envDef.label}
+                          </>
                         ) : (
-                          <Plug className="h-3.5 w-3.5" />
+                          "Other"
                         )}
-                      </Button>
+                      </div>
                     )}
-                    <Button
-                      size="icon"
-                      variant="ghost"
-                      className="h-7 w-7"
-                      onClick={() => onEdit(conn)}
-                    >
-                      <Pencil className="h-3.5 w-3.5" />
-                    </Button>
-                    <Button
-                      size="icon"
-                      variant="ghost"
-                      className="h-7 w-7 text-destructive"
-                      onClick={() => handleDelete(conn.id)}
-                      disabled={deleteMutation.isPending}
-                    >
-                      <Trash2 className="h-3.5 w-3.5" />
-                    </Button>
+                    {group.map((conn) => {
+                      const isConnected = connectedIds.has(conn.id);
+                      const isActive = activeConnectionId === conn.id;
+                      return (
+                        <div
+                          key={conn.id}
+                          className={`flex items-center gap-2 overflow-hidden rounded-md border p-3 mb-2 last:mb-0 ${
+                            isActive ? "border-primary bg-accent" : ""
+                          }`}
+                        >
+                          {conn.color ? (
+                            <span
+                              className="h-4 w-4 shrink-0 rounded-full"
+                              style={{ backgroundColor: conn.color }}
+                            />
+                          ) : (
+                            <Database className="h-4 w-4 shrink-0 text-muted-foreground" />
+                          )}
+                          <div className="min-w-0 flex-1">
+                            <div className="flex items-center gap-1.5 truncate text-sm font-medium">
+                              {conn.name}
+                              <EnvironmentBadge environment={conn.environment} size="sm" />
+                            </div>
+                            <div className="truncate text-xs text-muted-foreground">
+                              {conn.host}:{conn.port}/{conn.database}
+                            </div>
+                          </div>
+                          <div className="flex shrink-0 items-center gap-0.5">
+                            {isConnected ? (
+                              <Button
+                                size="icon"
+                                variant="ghost"
+                                className="h-7 w-7"
+                                onClick={() => handleDisconnect(conn.id)}
+                                disabled={disconnectMutation.isPending}
+                              >
+                                <Unplug className="h-3.5 w-3.5" />
+                              </Button>
+                            ) : (
+                              <Button
+                                size="icon"
+                                variant="ghost"
+                                className="h-7 w-7"
+                                onClick={() => handleConnect(conn)}
+                                disabled={connectMutation.isPending}
+                              >
+                                {connectMutation.isPending ? (
+                                  <Loader2 className="h-3.5 w-3.5 animate-spin" />
+                                ) : (
+                                  <Plug className="h-3.5 w-3.5" />
+                                )}
+                              </Button>
+                            )}
+                            <Button
+                              size="icon"
+                              variant="ghost"
+                              className="h-7 w-7"
+                              onClick={() => onEdit(conn)}
+                            >
+                              <Pencil className="h-3.5 w-3.5" />
+                            </Button>
+                            <Button
+                              size="icon"
+                              variant="ghost"
+                              className="h-7 w-7 text-destructive"
+                              onClick={() => handleDelete(conn.id)}
+                              disabled={deleteMutation.isPending}
+                            >
+                              <Trash2 className="h-3.5 w-3.5" />
+                            </Button>
+                          </div>
+                        </div>
+                      );
+                    })}
                   </div>
-                </div>
-              );
-            })}
-            {(!connections || connections.length === 0) && (
-              <div className="py-8 text-center text-sm text-muted-foreground">
-                No saved connections.
-                <br />
-                Click "New" to add one.
-              </div>
-            )}
+                );
+              });
+            })()}
           </div>
         </div>
       </SheetContent>
diff --git a/src/components/connections/ConnectionSelector.tsx b/src/components/connections/ConnectionSelector.tsx
index cf4ead7..271bdcc 100644
--- a/src/components/connections/ConnectionSelector.tsx
+++ b/src/components/connections/ConnectionSelector.tsx
@@ -7,6 +7,7 @@ import {
 } from "@/components/ui/select";
 import { useConnections } from "@/hooks/use-connections";
 import { useAppStore } from "@/stores/app-store";
+import { EnvironmentBadge } from "@/components/connections/EnvironmentBadge";
 
 export function ConnectionSelector() {
   const { data: connections } = useConnections();
@@ -37,6 +38,7 @@ export function ConnectionSelector() {
             />
           )}
           <SelectValue placeholder="Select connection" />
+          <EnvironmentBadge environment={activeConn?.environment} size="sm" />
         </div>
       </SelectTrigger>
       <SelectContent>
@@ -50,6 +52,7 @@ export function ConnectionSelector() {
                 />
               )}
               {conn.name}
+              <EnvironmentBadge environment={conn.environment} size="sm" />
             </div>
           </SelectItem>
         ))}
diff --git a/src/components/connections/EnvironmentBadge.tsx b/src/components/connections/EnvironmentBadge.tsx
new file mode 100644
index 0000000..ecc7abc
--- /dev/null
+++ b/src/components/connections/EnvironmentBadge.tsx
@@ -0,0 +1,26 @@
+import { getEnvironment } from "@/lib/environment";
+import { cn } from "@/lib/utils";
+
+interface Props {
+  environment?: string;
+  size?: "sm" | "md";
+}
+
+export function EnvironmentBadge({ environment, size = "sm" }: Props) {
+  const env = getEnvironment(environment);
+  if (!env) return null;
+
+  return (
+    <span
+      className={cn(
+        "inline-flex items-center rounded border font-semibold uppercase leading-none",
+        env.bgClass,
+        env.textClass,
+        env.borderClass,
+        size === "sm" ? "px-1.5 py-0.5 text-[10px]" : "px-2 py-0.5 text-xs"
+      )}
+    >
+      {env.label}
+    </span>
+  );
+}
diff --git a/src/components/layout/StatusBar.tsx b/src/components/layout/StatusBar.tsx
index fac808e..c5e82c1 100644
--- a/src/components/layout/StatusBar.tsx
+++ b/src/components/layout/StatusBar.tsx
@@ -1,6 +1,7 @@
 import { useAppStore } from "@/stores/app-store";
 import { useConnections } from "@/hooks/use-connections";
 import { Circle } from "lucide-react";
+import { EnvironmentBadge } from "@/components/connections/EnvironmentBadge";
 
 interface Props {
   rowCount?: number | null;
@@ -31,6 +32,7 @@ export function StatusBar({ rowCount, executionTime }: Props) {
             />
           )}
           {activeConn ? activeConn.name : "No connection"}
+          <EnvironmentBadge environment={activeConn?.environment} size="sm" />
         </span>
         {isConnected && activeConnectionId && (
           <span
diff --git a/src/components/layout/Toolbar.tsx b/src/components/layout/Toolbar.tsx
index 901099c..aae2657 100644
--- a/src/components/layout/Toolbar.tsx
+++ b/src/components/layout/Toolbar.tsx
@@ -9,6 +9,8 @@ import { useAppStore } from "@/stores/app-store";
 import { useConnections } from "@/hooks/use-connections";
 import { Database, Plus } from "lucide-react";
 import type { ConnectionConfig, Tab } from "@/types";
+import { getEnvironment } from "@/lib/environment";
+import { EnvironmentBadge } from "@/components/connections/EnvironmentBadge";
 
 export function Toolbar() {
   const [listOpen, setListOpen] = useState(false);
@@ -16,7 +18,9 @@ export function Toolbar() {
   const [editingConn, setEditingConn] = useState<ConnectionConfig | null>(null);
   const { activeConnectionId, addTab } = useAppStore();
   const { data: connections } = useConnections();
-  const activeColor = connections?.find((c) => c.id === activeConnectionId)?.color;
+  const activeConn = connections?.find((c) => c.id === activeConnectionId);
+  const activeEnv = getEnvironment(activeConn?.environment);
+  const activeColor = activeEnv?.color ?? activeConn?.color;
 
   const handleNewQuery = () => {
     if (!activeConnectionId) return;
@@ -54,6 +58,13 @@ export function Toolbar() {
 
         <ReadOnlyToggle />
 
+        {activeConn?.environment && (
+          <>
+            <Separator orientation="vertical" className="h-5" />
+            <EnvironmentBadge environment={activeConn.environment} size="sm" />
+          </>
+        )}
+
         <Separator orientation="vertical" className="h-5" />
 
         <Button
diff --git a/src/lib/environment.ts b/src/lib/environment.ts
new file mode 100644
index 0000000..9dcfb1c
--- /dev/null
+++ b/src/lib/environment.ts
@@ -0,0 +1,13 @@
+export const ENVIRONMENTS = [
+  { value: "local", label: "LOCAL", color: "#6b7280", bgClass: "bg-gray-500/20",  textClass: "text-gray-400",  borderClass: "border-gray-500/40"  },
+  { value: "dev",   label: "DEV",   color: "#3b82f6", bgClass: "bg-blue-500/20",  textClass: "text-blue-400",  borderClass: "border-blue-500/40"  },
+  { value: "stage", label: "STG",   color: "#f59e0b", bgClass: "bg-amber-500/20", textClass: "text-amber-400", borderClass: "border-amber-500/40" },
+  { value: "prod",  label: "PROD",  color: "#ef4444", bgClass: "bg-red-500/20",   textClass: "text-red-400",   borderClass: "border-red-500/40"   },
+] as const;
+
+export type EnvironmentValue = (typeof ENVIRONMENTS)[number]["value"];
+
+export function getEnvironment(value?: string) {
+  if (!value) return null;
+  return ENVIRONMENTS.find((e) => e.value === value) ?? null;
+}
diff --git a/src/types/index.ts b/src/types/index.ts
index 08449f5..22f109c 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -8,6 +8,7 @@ export interface ConnectionConfig {
   database: string;
   ssl_mode?: string;
   color?: string;
+  environment?: string;
 }
 
 export interface QueryResult {