diff --git a/docs/changelog/112850.yaml b/docs/changelog/112850.yaml
new file mode 100644
index 0000000000000..97a8877f6291c
--- /dev/null
+++ b/docs/changelog/112850.yaml
@@ -0,0 +1,5 @@
+pr: 112850
+summary: Fix synthetic source field names for multi-fields
+area: Mapping
+type: bug
+issues: []
diff --git a/modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/extras/MatchOnlyTextFieldMapper.java b/modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/extras/MatchOnlyTextFieldMapper.java
index a616fe9c20c26..6bcad389c34b7 100644
--- a/modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/extras/MatchOnlyTextFieldMapper.java
+++ b/modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/extras/MatchOnlyTextFieldMapper.java
@@ -433,7 +433,7 @@ public MatchOnlyTextFieldType fieldType() {
 
     @Override
     protected SyntheticSourceSupport syntheticSourceSupport() {
-        var loader = new StringStoredFieldFieldLoader(fieldType().storedFieldNameForSyntheticSource(), leafName()) {
+        var loader = new StringStoredFieldFieldLoader(fieldType().storedFieldNameForSyntheticSource(), fieldType().name(), leafName()) {
             @Override
             protected void write(XContentBuilder b, Object value) throws IOException {
                 b.value((String) value);
diff --git a/plugins/mapper-annotated-text/src/main/java/org/elasticsearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java b/plugins/mapper-annotated-text/src/main/java/org/elasticsearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java
index b66ce41d3259d..c046fb3fcc4f0 100644
--- a/plugins/mapper-annotated-text/src/main/java/org/elasticsearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java
+++ b/plugins/mapper-annotated-text/src/main/java/org/elasticsearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java
@@ -582,7 +582,7 @@ protected void write(XContentBuilder b, Object value) throws IOException {
 
         var kwd = TextFieldMapper.SyntheticSourceHelper.getKeywordFieldMapperForSyntheticSource(this);
         if (kwd != null) {
-            return new SyntheticSourceSupport.Native(kwd.syntheticFieldLoader(leafName()));
+            return new SyntheticSourceSupport.Native(kwd.syntheticFieldLoader(fullPath(), leafName()));
         }
 
         return super.syntheticSourceSupport();
diff --git a/server/src/main/java/org/elasticsearch/index/mapper/KeywordFieldMapper.java b/server/src/main/java/org/elasticsearch/index/mapper/KeywordFieldMapper.java
index 97c48c7bbfa36..6b563e93b073a 100644
--- a/server/src/main/java/org/elasticsearch/index/mapper/KeywordFieldMapper.java
+++ b/server/src/main/java/org/elasticsearch/index/mapper/KeywordFieldMapper.java
@@ -1037,13 +1037,13 @@ protected SyntheticSourceSupport syntheticSourceSupport() {
         }
 
         if (fieldType.stored() || hasDocValues) {
-            return new SyntheticSourceSupport.Native(syntheticFieldLoader(leafName()));
+            return new SyntheticSourceSupport.Native(syntheticFieldLoader(fullPath(), leafName()));
         }
 
         return super.syntheticSourceSupport();
     }
 
-    public SourceLoader.SyntheticFieldLoader syntheticFieldLoader(String simpleName) {
+    public SourceLoader.SyntheticFieldLoader syntheticFieldLoader(String fullFieldName, String leafFieldName) {
         assert fieldType.stored() || hasDocValues;
 
         var layers = new ArrayList<CompositeSyntheticFieldLoader.Layer>();
@@ -1081,6 +1081,6 @@ protected void writeValue(Object value, XContentBuilder b) throws IOException {
             });
         }
 
-        return new CompositeSyntheticFieldLoader(simpleName, fullPath(), layers);
+        return new CompositeSyntheticFieldLoader(leafFieldName, fullFieldName, layers);
     }
 }
diff --git a/server/src/main/java/org/elasticsearch/index/mapper/StringStoredFieldFieldLoader.java b/server/src/main/java/org/elasticsearch/index/mapper/StringStoredFieldFieldLoader.java
index a539bda6eaa41..44990c094295d 100644
--- a/server/src/main/java/org/elasticsearch/index/mapper/StringStoredFieldFieldLoader.java
+++ b/server/src/main/java/org/elasticsearch/index/mapper/StringStoredFieldFieldLoader.java
@@ -19,19 +19,25 @@
 import static java.util.Collections.emptyList;
 
 public abstract class StringStoredFieldFieldLoader implements SourceLoader.SyntheticFieldLoader {
-    private final String name;
+    private final String storedFieldLoaderName;
+    private final String fullName;
     private final String simpleName;
 
     private List<Object> values = emptyList();
 
-    public StringStoredFieldFieldLoader(String name, String simpleName) {
-        this.name = name;
+    public StringStoredFieldFieldLoader(String fullName, String simpleName) {
+        this(fullName, fullName, simpleName);
+    }
+
+    public StringStoredFieldFieldLoader(String storedFieldLoaderName, String fullName, String simpleName) {
+        this.storedFieldLoaderName = storedFieldLoaderName;
+        this.fullName = fullName;
         this.simpleName = simpleName;
     }
 
     @Override
     public final Stream<Map.Entry<String, StoredFieldLoader>> storedFieldLoaders() {
-        return Stream.of(Map.entry(name, newValues -> values = newValues));
+        return Stream.of(Map.entry(storedFieldLoaderName, newValues -> values = newValues));
     }
 
     @Override
@@ -72,6 +78,6 @@ public final DocValuesLoader docValuesLoader(LeafReader reader, int[] docIdsInLe
 
     @Override
     public String fieldName() {
-        return name;
+        return fullName;
     }
 }
diff --git a/server/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java b/server/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java
index 8c8396c7a9bb7..972e9e415ce94 100644
--- a/server/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java
+++ b/server/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java
@@ -1462,7 +1462,7 @@ protected void write(XContentBuilder b, Object value) throws IOException {
 
         var kwd = SyntheticSourceHelper.getKeywordFieldMapperForSyntheticSource(this);
         if (kwd != null) {
-            return new SyntheticSourceSupport.Native(kwd.syntheticFieldLoader(leafName()));
+            return new SyntheticSourceSupport.Native(kwd.syntheticFieldLoader(fullPath(), leafName()));
         }
 
         return super.syntheticSourceSupport();