diff --git a/packages/compiler-cli/test/ngtsc/template_typecheck_spec.ts b/packages/compiler-cli/test/ngtsc/template_typecheck_spec.ts
index 63c6a168eb052..26212e3bc1e64 100644
--- a/packages/compiler-cli/test/ngtsc/template_typecheck_spec.ts
+++ b/packages/compiler-cli/test/ngtsc/template_typecheck_spec.ts
@@ -2017,6 +2017,28 @@ export declare class AnimationEvent {
         expect(diags.length).toBe(0);
       });
 
+      it('should allow HTML elements without explicit namespace inside SVG foreignObject', () => {
+        env.write('test.ts', `
+        import {Component, NgModule} from '@angular/core';
+        @Component({
+          template: \`
+            <svg>
+              <foreignObject>
+                <div>Hello</div>
+              </foreignObject>
+            </svg>
+          \`,
+        })
+        export class FooCmp {}
+        @NgModule({
+          declarations: [FooCmp],
+        })
+        export class FooModule {}
+      `);
+        const diags = env.driveDiagnostics();
+        expect(diags.length).toBe(0);
+      });
+
       it('should check for unknown elements inside an SVG foreignObject', () => {
         env.write('test.ts', `
         import {Component, NgModule} from '@angular/core';
@@ -2042,6 +2064,33 @@ export declare class AnimationEvent {
 1. If 'foo' is an Angular component, then verify that it is part of this module.
 2. To allow any element add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component.`);
       });
+
+      it('should check for unknown elements without explicit namespace inside an SVG foreignObject',
+         () => {
+           env.write('test.ts', `
+        import {Component, NgModule} from '@angular/core';
+        @Component({
+          selector: 'blah',
+          template: \`
+            <svg>
+              <foreignObject>
+                <foo>Hello</foo>
+              </foreignObject>
+            </svg>
+          \`,
+        })
+        export class FooCmp {}
+        @NgModule({
+          declarations: [FooCmp],
+        })
+        export class FooModule {}
+      `);
+           const diags = env.driveDiagnostics();
+           expect(diags.length).toBe(1);
+           expect(diags[0].messageText).toBe(`'foo' is not a known element:
+1. If 'foo' is an Angular component, then verify that it is part of this module.
+2. To allow any element add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component.`);
+         });
     });
 
     // Test both sync and async compilations, see https://github.com/angular/angular/issues/32538
diff --git a/packages/compiler/src/ml_parser/html_tags.ts b/packages/compiler/src/ml_parser/html_tags.ts
index 969fb0f95fac2..e83d7aa670ab4 100644
--- a/packages/compiler/src/ml_parser/html_tags.ts
+++ b/packages/compiler/src/ml_parser/html_tags.ts
@@ -17,6 +17,7 @@ export class HtmlTagDefinition implements TagDefinition {
   isVoid: boolean;
   ignoreFirstLf: boolean;
   canSelfClose: boolean = false;
+  preventNamespaceInheritance: boolean;
 
   constructor({
     closedByChildren,
@@ -24,14 +25,16 @@ export class HtmlTagDefinition implements TagDefinition {
     contentType = TagContentType.PARSABLE_DATA,
     closedByParent = false,
     isVoid = false,
-    ignoreFirstLf = false
+    ignoreFirstLf = false,
+    preventNamespaceInheritance = false
   }: {
     closedByChildren?: string[],
     closedByParent?: boolean,
     implicitNamespacePrefix?: string,
     contentType?: TagContentType,
     isVoid?: boolean,
-    ignoreFirstLf?: boolean
+    ignoreFirstLf?: boolean,
+    preventNamespaceInheritance?: boolean
   } = {}) {
     if (closedByChildren && closedByChildren.length > 0) {
       closedByChildren.forEach(tagName => this.closedByChildren[tagName] = true);
@@ -41,6 +44,7 @@ export class HtmlTagDefinition implements TagDefinition {
     this.implicitNamespacePrefix = implicitNamespacePrefix || null;
     this.contentType = contentType;
     this.ignoreFirstLf = ignoreFirstLf;
+    this.preventNamespaceInheritance = preventNamespaceInheritance;
   }
 
   isClosedByChild(name: string): boolean {
@@ -88,6 +92,17 @@ export function getHtmlTagDefinition(tagName: string): HtmlTagDefinition {
       'th': new HtmlTagDefinition({closedByChildren: ['td', 'th'], closedByParent: true}),
       'col': new HtmlTagDefinition({isVoid: true}),
       'svg': new HtmlTagDefinition({implicitNamespacePrefix: 'svg'}),
+      'foreignObject': new HtmlTagDefinition({
+        // Usually the implicit namespace here would be redundant since it will be inherited from
+        // the parent `svg`, but we have to do it for `foreignObject`, because the way the parser
+        // works is that the parent node of an end tag is its own start tag which means that
+        // the `preventNamespaceInheritance` on `foreignObject` would have it default to the
+        // implicit namespace which is `html`, unless specified otherwise.
+        implicitNamespacePrefix: 'svg',
+        // We want to prevent children of foreignObject from inheriting its namespace, because
+        // the point of the element is to allow nodes from other namespaces to be inserted.
+        preventNamespaceInheritance: true,
+      }),
       'math': new HtmlTagDefinition({implicitNamespacePrefix: 'math'}),
       'li': new HtmlTagDefinition({closedByChildren: ['li'], closedByParent: true}),
       'dt': new HtmlTagDefinition({closedByChildren: ['dt', 'dd']}),
@@ -111,5 +126,8 @@ export function getHtmlTagDefinition(tagName: string): HtmlTagDefinition {
           {contentType: TagContentType.ESCAPABLE_RAW_TEXT, ignoreFirstLf: true}),
     };
   }
-  return TAG_DEFINITIONS[tagName.toLowerCase()] || _DEFAULT_TAG_DEFINITION;
+  // We have to make both a case-sensitive and a case-insesitive lookup, because
+  // HTML tag names are case insensitive, whereas some SVG tags are case sensitive.
+  return TAG_DEFINITIONS[tagName] ?? TAG_DEFINITIONS[tagName.toLowerCase()] ??
+      _DEFAULT_TAG_DEFINITION;
 }
diff --git a/packages/compiler/src/ml_parser/parser.ts b/packages/compiler/src/ml_parser/parser.ts
index b31db0c25cfc0..3d3131989cdc7 100644
--- a/packages/compiler/src/ml_parser/parser.ts
+++ b/packages/compiler/src/ml_parser/parser.ts
@@ -10,7 +10,7 @@ import {ParseError, ParseSourceSpan} from '../parse_util';
 
 import * as html from './ast';
 import * as lex from './lexer';
-import {getNsPrefix, isNgContainer, mergeNsAndName, TagDefinition} from './tags';
+import {getNsPrefix, mergeNsAndName, splitNsName, TagDefinition} from './tags';
 
 export class TreeError extends ParseError {
   static create(elementName: string|null, span: ParseSourceSpan, msg: string): TreeError {
@@ -353,7 +353,11 @@ class _TreeBuilder {
     if (prefix === '') {
       prefix = this.getTagDefinition(localName).implicitNamespacePrefix || '';
       if (prefix === '' && parentElement != null) {
-        prefix = getNsPrefix(parentElement.name);
+        const parentTagName = splitNsName(parentElement.name)[1];
+        const parentTagDefinition = this.getTagDefinition(parentTagName);
+        if (!parentTagDefinition.preventNamespaceInheritance) {
+          prefix = getNsPrefix(parentElement.name);
+        }
       }
     }
 
diff --git a/packages/compiler/src/ml_parser/tags.ts b/packages/compiler/src/ml_parser/tags.ts
index 279ab0aacb78e..32b3aab2af624 100644
--- a/packages/compiler/src/ml_parser/tags.ts
+++ b/packages/compiler/src/ml_parser/tags.ts
@@ -19,6 +19,7 @@ export interface TagDefinition {
   isVoid: boolean;
   ignoreFirstLf: boolean;
   canSelfClose: boolean;
+  preventNamespaceInheritance: boolean;
 
   isClosedByChild(name: string): boolean;
 }
diff --git a/packages/compiler/src/ml_parser/xml_tags.ts b/packages/compiler/src/ml_parser/xml_tags.ts
index 81af50d6898e3..e4a76ed2456b0 100644
--- a/packages/compiler/src/ml_parser/xml_tags.ts
+++ b/packages/compiler/src/ml_parser/xml_tags.ts
@@ -20,6 +20,7 @@ export class XmlTagDefinition implements TagDefinition {
   isVoid: boolean = false;
   ignoreFirstLf: boolean = false;
   canSelfClose: boolean = true;
+  preventNamespaceInheritance: boolean = false;
 
   requireExtraParent(currentParent: string): boolean {
     return false;