diff --git a/types/hotwired__turbo/hotwired__turbo-tests.ts b/types/hotwired__turbo/hotwired__turbo-tests.ts
index 5e3f6a582d3f63..f41a07a13381c1 100644
--- a/types/hotwired__turbo/hotwired__turbo-tests.ts
+++ b/types/hotwired__turbo/hotwired__turbo-tests.ts
@@ -16,6 +16,8 @@ import {
     StreamMessage,
     StreamSource,
     TurboHistory,
+    TurboStreamAction,
+    TurboStreamActions,
     Visit,
     visit,
     VisitOptions,
@@ -102,6 +104,19 @@ StreamActions.log = function() {
     console.log(this.getAttribute("message"));
 };
 
+// Test TurboStreamActions / TurboStreamAction exports
+// $ExpectType TurboStreamActions
+StreamActions;
+
+const customStreamAction: TurboStreamAction = function() {
+    // $ExpectType StreamElement
+    this;
+};
+StreamActions.custom = customStreamAction;
+
+const allStreamActions: TurboStreamActions = StreamActions;
+allStreamActions.log;
+
 document.addEventListener("turbo:before-fetch-request", function(event) {
     // $ExpectType FetchRequestHeaders
     const headers = event.detail.fetchOptions.headers;
@@ -272,6 +287,12 @@ turboStream.templateElement = document.createElement("template");
 // @ts-expect-error - templateContent is readonly
 turboStream.templateContent = document.createDocumentFragment();
 
+// Test StreamElement.targetElements
+// $ExpectType Element[]
+turboStream.targetElements;
+// @ts-expect-error - targetElements is readonly
+turboStream.targetElements = [];
+
 const eventSource = new EventSource("https://example.com/stream");
 const webSocket = new WebSocket("wss://example.com/stream");
 
diff --git a/types/hotwired__turbo/index.d.ts b/types/hotwired__turbo/index.d.ts
index fa0c1ce206aec8..2169414fc32b8b 100644
--- a/types/hotwired__turbo/index.d.ts
+++ b/types/hotwired__turbo/index.d.ts
@@ -51,6 +51,13 @@ export class StreamElement extends HTMLElement {
      * Gets a cloned copy of the template's content.
      */
     readonly templateContent: DocumentFragment;
+
+    /**
+     * Gets the list of elements the stream action will be applied to,
+     * resolved from the `target` (an element ID) or `targets` (a CSS
+     * selector) attribute.
+     */
+    readonly targetElements: Element[];
 }
 
 export class StreamSourceElement extends HTMLElement {
@@ -299,9 +306,19 @@ export interface TurboSession {
     readonly restorationIdentifier: string;
 }
 
-export const StreamActions: {
-    [action: string]: (this: StreamElement) => void;
-};
+/**
+ * A stream action callback. Invoked with the matched `StreamElement` as
+ * `this`, allowing access to its attributes and target elements.
+ */
+export type TurboStreamAction = (this: StreamElement) => void;
+
+/**
+ * A map of action names to their {@link TurboStreamAction} callbacks, as
+ * used by {@link StreamActions}.
+ */
+export type TurboStreamActions = Record<string, TurboStreamAction>;
+
+export const StreamActions: TurboStreamActions;
 
 export type Action = "advance" | "replace" | "restore";
 export interface VisitOptions {
@@ -457,9 +474,7 @@ export interface TurboGlobal {
     navigator: Navigator;
     cache: Cache;
     config: TurboConfig;
-    StreamActions: {
-        [action: string]: (this: StreamElement) => void;
-    };
+    StreamActions: TurboStreamActions;
 }
 
 declare global {