diff --git a/grails-spring/src/main/groovy/org/grails/spring/GrailsApplicationContext.java b/grails-spring/src/main/groovy/org/grails/spring/GrailsApplicationContext.java
index e0e85ad219a..40bbe2daa82 100644
--- a/grails-spring/src/main/groovy/org/grails/spring/GrailsApplicationContext.java
+++ b/grails-spring/src/main/groovy/org/grails/spring/GrailsApplicationContext.java
@@ -98,12 +98,25 @@ public void setMetaClass(MetaClass metaClass) {
 
     /**
      * Initialize the theme capability.
+     *
+     * @deprecated since 7.1, for removal in 8.0. Spring's theme support ({@link ThemeSource},
+     * {@link UiApplicationContextUtils#initThemeSource}) is deprecated in Spring Boot 3 and
+     * removed in Spring Boot 4. This method will be removed in Grails 8.0.0.
      */
+    @Deprecated(since = "7.1", forRemoval = true)
     @Override
     protected void onRefresh() {
         themeSource = UiApplicationContextUtils.initThemeSource(this);
     }
 
+    /**
+     * Return the {@link Theme} instance for the given theme name.
+     *
+     * @deprecated since 7.1, for removal in 8.0. Spring's theme support ({@link ThemeSource},
+     * {@link Theme}) is deprecated in Spring Boot 3 and removed in Spring Boot 4.
+     * This method will be removed in Grails 8.0.0.
+     */
+    @Deprecated(since = "7.1", forRemoval = true)
     public Theme getTheme(String themeName) {
         return themeSource.getTheme(themeName);
     }
diff --git a/grails-web-core/src/main/groovy/grails/web/servlet/context/GrailsWebApplicationContext.java b/grails-web-core/src/main/groovy/grails/web/servlet/context/GrailsWebApplicationContext.java
index 46fe8cbb13c..fa91e4b9eaf 100644
--- a/grails-web-core/src/main/groovy/grails/web/servlet/context/GrailsWebApplicationContext.java
+++ b/grails-web-core/src/main/groovy/grails/web/servlet/context/GrailsWebApplicationContext.java
@@ -48,6 +48,10 @@
  * A WebApplicationContext that extends StaticApplicationContext to allow for programmatic
  * configuration at runtime. The code is adapted from StaticWebApplicationContext.
  *
+ * <p>Note: The {@link ThemeSource} interface implementation is deprecated since Grails 7.1 and
+ * will be removed in Grails 8.0.0. Spring's theme support is deprecated in Spring Boot 3 and
+ * removed in Spring Boot 4.
+ *
  * @author Graeme
  * @since 0.3
  */