diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/270_wildcard_fieldtype_queries.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/270_wildcard_fieldtype_queries.yml
index cd7ac1450563f..4415aa19edb2f 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search/270_wildcard_fieldtype_queries.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/270_wildcard_fieldtype_queries.yml
@@ -50,6 +50,10 @@ setup:
         id: 5
         body:
           my_field: "AbCd"
+  - do:
+      index:
+        index: test
+        id: 6
   - do:
       indices.refresh: {}
 
@@ -198,3 +202,26 @@ setup:
               my_field:
                 value: ".*06-08.*Cluster-Manager Node.*"
   - match: { hits.total.value: 0 }
+
+---
+"wildcard match-all works":
+  - do:
+      search:
+        index: test
+        body:
+          query:
+            wildcard:
+              my_field:
+                value: "*"
+  - match: { hits.total.value: 5 }
+---
+"regexp match-all works":
+  - do:
+      search:
+        index: test
+        body:
+          query:
+            wildcard:
+              my_field:
+                value: ".*"
+  - match: { hits.total.value: 5 }
diff --git a/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java
index 3739a07e425bd..15f1a1b15abd1 100644
--- a/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java
@@ -448,14 +448,14 @@ public Query wildcardQuery(String value, MultiTermQuery.RewriteMethod method, bo
                 };
             }
 
-            return new WildcardMatchingQuery(
-                name(),
-                matchAllTermsQuery(name(), getRequiredNGrams(finalValue)),
-                matchPredicate,
-                value,
-                context,
-                this
-            );
+            Set<String> requiredNGrams = getRequiredNGrams(finalValue);
+            Query approximation;
+            if (requiredNGrams.isEmpty()) {
+                approximation = this.existsQuery(context);
+            } else {
+                approximation = matchAllTermsQuery(name(), requiredNGrams);
+            }
+            return new WildcardMatchingQuery(name(), approximation, matchPredicate, value, context, this);
         }
 
         // Package-private for testing
@@ -540,7 +540,11 @@ public Query regexpQuery(
             Automaton automaton = regExp.toAutomaton(maxDeterminizedStates);
             CompiledAutomaton compiledAutomaton = new CompiledAutomaton(automaton);
 
-            return new WildcardMatchingQuery(name(), regexpToQuery(name(), regExp), s -> {
+            Query approximation = regexpToQuery(name(), regExp);
+            if (approximation instanceof MatchAllDocsQuery) {
+                approximation = existsQuery(context);
+            }
+            return new WildcardMatchingQuery(name(), approximation, s -> {
                 BytesRef valueBytes = BytesRefs.toBytesRef(s);
                 return compiledAutomaton.runAutomaton.run(valueBytes.bytes, valueBytes.offset, valueBytes.length);
             }, "/" + value + "/", context, this);
@@ -704,7 +708,7 @@ private WildcardMatchingQuery(
 
         @Override
         public String toString(String s) {
-            return "WildcardMatchingQuery(" + fieldName + "\"" + patternString + "\")";
+            return "WildcardMatchingQuery(" + fieldName + ":\"" + patternString + "\")";
         }
 
         @Override
diff --git a/server/src/test/java/org/opensearch/index/mapper/WildcardFieldTypeTests.java b/server/src/test/java/org/opensearch/index/mapper/WildcardFieldTypeTests.java
index f03364054c166..ac76c79132844 100644
--- a/server/src/test/java/org/opensearch/index/mapper/WildcardFieldTypeTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/WildcardFieldTypeTests.java
@@ -149,4 +149,18 @@ public void testRegexpQuery() {
         assertTrue(actualMatchingQuery.getSecondPhaseMatcher().test("abcdjk"));
         assertTrue(actualMatchingQuery.getSecondPhaseMatcher().test("abefqwertyhi"));
     }
+
+    public void testWildcardMatchAll() {
+        String pattern = "*";
+        MappedFieldType ft = new WildcardFieldMapper.WildcardFieldType("field");
+        Query actual = ft.wildcardQuery(pattern, null, null);
+        assertEquals(new WildcardFieldMapper.WildcardMatchingQuery("field", ft.existsQuery(null), "*"), actual);
+    }
+
+    public void testRegexpMatchAll() {
+        String pattern = ".*";
+        MappedFieldType ft = new WildcardFieldMapper.WildcardFieldType("field");
+        Query actual = ft.regexpQuery(pattern, 0, 0, 1000, null, null);
+        assertEquals(new WildcardFieldMapper.WildcardMatchingQuery("field", ft.existsQuery(null), "/.*/"), actual);
+    }
 }