diff --git a/tsc/internal/transformers/estransforms/optionalchain.go b/tsc/internal/transformers/estransforms/optionalchain.go
index 33b269280f594..605795d8b38bf 100644
--- a/tsc/internal/transformers/estransforms/optionalchain.go
+++ b/tsc/internal/transformers/estransforms/optionalchain.go
@@ -140,6 +140,10 @@ func flattenChain(chain *ast.Node) flattenResult {
 		debug.Assert(!isNonNullChain(chain))
 		links = append([]*ast.Node{chain}, links...)
 	}
+	if ast.IsTaggedTemplateExpression(chain) {
+		// A tagged template has no expression; its tag is the base of the chain.
+		return flattenResult{chain.AsTaggedTemplateExpression().Tag, links}
+	}
 	return flattenResult{chain.Expression(), links}
 }
 
@@ -204,6 +208,17 @@ func (ch *optionalChainTransformer) visitOptionalExpression(node *ast.Node, capt
 					ast.NodeFlagsNone,
 				)
 			}
+		case ast.KindTaggedTemplateExpression:
+			// A tagged template can only be the head of the chain (flattenChain
+			// stops walking at it); re-tag its template onto the checked base.
+			t := segment.AsTaggedTemplateExpression()
+			rightExpression = ch.Factory().NewTaggedTemplateExpression(
+				rightExpression,
+				nil, /*questionDotToken*/
+				t.TypeArguments,
+				ch.Visitor().VisitNode(t.Template),
+				ast.NodeFlagsNone,
+			)
 		}
 		ch.EmitContext().SetOriginal(rightExpression, segment)
 	}
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).errors.txt b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).errors.txt
new file mode 100644
index 0000000000000..703ee75bc68d7
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).errors.txt
@@ -0,0 +1,26 @@
+repro.ts(1,1): error TS2304: Cannot find name 'e'.
+repro.ts(2,1): error TS1005: ')' expected.
+siblings.ts(2,5): error TS1358: Tagged template expressions are not permitted in an optional chain.
+siblings.ts(3,5): error TS1358: Tagged template expressions are not permitted in an optional chain.
+siblings.ts(4,4): error TS1358: Tagged template expressions are not permitted in an optional chain.
+
+
+==== repro.ts (2 errors) ====
+    e?.``(
+    ~
+!!! error TS2304: Cannot find name 'e'.
+    
+    
+!!! error TS1005: ')' expected.
+==== siblings.ts (3 errors) ====
+    declare var a: any;
+    a?.b`c`;
+        ~~~
+!!! error TS1358: Tagged template expressions are not permitted in an optional chain.
+    a?.b`c`();
+        ~~~
+!!! error TS1358: Tagged template expressions are not permitted in an optional chain.
+    a?.``.x;
+       ~~
+!!! error TS1358: Tagged template expressions are not permitted in an optional chain.
+    
\ No newline at end of file
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).js b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).js
new file mode 100644
index 0000000000000..a66557579d6f5
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).js
@@ -0,0 +1,21 @@
+//// [tests/cases/compiler/optionalChainTaggedTemplate.ts] ////
+
+//// [repro.ts]
+e?.``(
+
+//// [siblings.ts]
+declare var a: any;
+a?.b`c`;
+a?.b`c`();
+a?.``.x;
+
+
+//// [repro.js]
+"use strict";
+e === null || e === void 0 ? void 0 : e ``();
+//// [siblings.js]
+"use strict";
+var _a;
+(a === null || a === void 0 ? void 0 : a.b) `c`;
+(_a = a === null || a === void 0 ? void 0 : a.b) === null || _a === void 0 ? void 0 : _a `c`();
+a === null || a === void 0 ? void 0 : a ``.x;
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).symbols b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).symbols
new file mode 100644
index 0000000000000..f1def366b522e
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).symbols
@@ -0,0 +1,19 @@
+//// [tests/cases/compiler/optionalChainTaggedTemplate.ts] ////
+
+=== repro.ts ===
+
+e?.``(
+
+=== siblings.ts ===
+declare var a: any;
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
+a?.b`c`;
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
+a?.b`c`();
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
+a?.``.x;
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).types b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).types
new file mode 100644
index 0000000000000..ebe370e79967b
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2017).types
@@ -0,0 +1,35 @@
+//// [tests/cases/compiler/optionalChainTaggedTemplate.ts] ////
+
+=== repro.ts ===
+e?.``(
+>e?.``( : any
+>e?.`` : any
+>e : any
+>`` : ""
+
+=== siblings.ts ===
+declare var a: any;
+>a : any
+
+a?.b`c`;
+>a?.b`c` : any
+>a?.b : any
+>a : any
+>b : any
+>`c` : "c"
+
+a?.b`c`();
+>a?.b`c`() : any
+>a?.b`c` : any
+>a?.b : any
+>a : any
+>b : any
+>`c` : "c"
+
+a?.``.x;
+>a?.``.x : any
+>a?.`` : any
+>a : any
+>`` : ""
+>x : any
+
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).errors.txt b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).errors.txt
new file mode 100644
index 0000000000000..703ee75bc68d7
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).errors.txt
@@ -0,0 +1,26 @@
+repro.ts(1,1): error TS2304: Cannot find name 'e'.
+repro.ts(2,1): error TS1005: ')' expected.
+siblings.ts(2,5): error TS1358: Tagged template expressions are not permitted in an optional chain.
+siblings.ts(3,5): error TS1358: Tagged template expressions are not permitted in an optional chain.
+siblings.ts(4,4): error TS1358: Tagged template expressions are not permitted in an optional chain.
+
+
+==== repro.ts (2 errors) ====
+    e?.``(
+    ~
+!!! error TS2304: Cannot find name 'e'.
+    
+    
+!!! error TS1005: ')' expected.
+==== siblings.ts (3 errors) ====
+    declare var a: any;
+    a?.b`c`;
+        ~~~
+!!! error TS1358: Tagged template expressions are not permitted in an optional chain.
+    a?.b`c`();
+        ~~~
+!!! error TS1358: Tagged template expressions are not permitted in an optional chain.
+    a?.``.x;
+       ~~
+!!! error TS1358: Tagged template expressions are not permitted in an optional chain.
+    
\ No newline at end of file
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).js b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).js
new file mode 100644
index 0000000000000..d84b438b9c953
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).js
@@ -0,0 +1,20 @@
+//// [tests/cases/compiler/optionalChainTaggedTemplate.ts] ////
+
+//// [repro.ts]
+e?.``(
+
+//// [siblings.ts]
+declare var a: any;
+a?.b`c`;
+a?.b`c`();
+a?.``.x;
+
+
+//// [repro.js]
+"use strict";
+e ``();
+//// [siblings.js]
+"use strict";
+(a?.b) `c`;
+(a?.b) `c`();
+a ``.x;
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).symbols b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).symbols
new file mode 100644
index 0000000000000..f1def366b522e
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).symbols
@@ -0,0 +1,19 @@
+//// [tests/cases/compiler/optionalChainTaggedTemplate.ts] ////
+
+=== repro.ts ===
+
+e?.``(
+
+=== siblings.ts ===
+declare var a: any;
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
+a?.b`c`;
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
+a?.b`c`();
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
+a?.``.x;
+>a : Symbol(a, Decl(siblings.ts, 0, 11))
+
diff --git a/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).types b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).types
new file mode 100644
index 0000000000000..ebe370e79967b
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/optionalChainTaggedTemplate(target=es2024).types
@@ -0,0 +1,35 @@
+//// [tests/cases/compiler/optionalChainTaggedTemplate.ts] ////
+
+=== repro.ts ===
+e?.``(
+>e?.``( : any
+>e?.`` : any
+>e : any
+>`` : ""
+
+=== siblings.ts ===
+declare var a: any;
+>a : any
+
+a?.b`c`;
+>a?.b`c` : any
+>a?.b : any
+>a : any
+>b : any
+>`c` : "c"
+
+a?.b`c`();
+>a?.b`c`() : any
+>a?.b`c` : any
+>a?.b : any
+>a : any
+>b : any
+>`c` : "c"
+
+a?.``.x;
+>a?.``.x : any
+>a?.`` : any
+>a : any
+>`` : ""
+>x : any
+
diff --git a/tsc/testdata/tests/cases/compiler/optionalChainTaggedTemplate.ts b/tsc/testdata/tests/cases/compiler/optionalChainTaggedTemplate.ts
new file mode 100644
index 0000000000000..39609cdd1004c
--- /dev/null
+++ b/tsc/testdata/tests/cases/compiler/optionalChainTaggedTemplate.ts
@@ -0,0 +1,10 @@
+// @target: es2017, es2024
+
+// @filename: repro.ts
+e?.``(
+
+// @filename: siblings.ts
+declare var a: any;
+a?.b`c`;
+a?.b`c`();
+a?.``.x;