diff --git a/doc/base/classes.xml b/doc/base/classes.xml
index cafb1449158..47fa1deb551 100644
--- a/doc/base/classes.xml
+++ b/doc/base/classes.xml
@@ -32582,7 +32582,7 @@
 			<argument index="2" name="end" type="int" default="-1">
 			</argument>
 			<description>
-				Searches the text for the compiled pattern. Returns a [RegExMatch] container of the first matching reult if found, otherwise null. The starting point of the serch could be specified without moving the string start anchor.
+				Searches the text for the compiled pattern. Returns a [RegExMatch] container of the first matching reult if found, otherwise null. The region to search within can be specified without modifying where the start and end anchor would be.
 			</description>
 		</method>
 		<method name="sub" qualifiers="const">
@@ -32590,14 +32590,16 @@
 			</return>
 			<argument index="0" name="text" type="String">
 			</argument>
-			<argument index="1" name="template" type="String">
+			<argument index="1" name="replacement" type="String">
 			</argument>
-			<argument index="2" name="start" type="int" default="0">
+			<argument index="2" name="all" type="bool" default="false">
 			</argument>
-			<argument index="3" name="end" type="int" default="-1">
+			<argument index="3" name="start" type="int" default="0">
+			</argument>
+			<argument index="4" name="end" type="int" default="-1">
 			</argument>
 			<description>
-				Searches the specified text for the compiled pattern and returns the text with the result replaced. Escapes and backreferences such as [code]\1[/code] and [code]\g&lt;name&gt;[/code] are automatically expanded and resolved. If no change was found the unmodified text is returned instead.
+				Searches the text for the compiled pattern and replaces it with the specified string. Escapes and backreferences such as [code]\1[/code] and [code]\g&lt;name&gt;[/code] expanded and resolved. By default only the first instance is replaced but it can be changed for all instances (global replacement). The region to search within can be specified without modifying where the start and end anchor would be.
 			</description>
 		</method>
 	</methods>
@@ -32616,7 +32618,7 @@
 			<argument index="0" name="template" type="String">
 			</argument>
 			<description>
-				Using results from the search, returns the specified string with escapes and backreferences such as [code]\1[/code] and [code]\g&lt;name&gt;[/code] expanded and resolved
+				Using results from the search, returns the specified string with escapes and backreferences such as [code]\1[/code] and [code]\g&lt;name&gt;[/code] expanded and resolved.
 			</description>
 		</method>
 		<method name="get_end" qualifiers="const">
diff --git a/modules/regex/regex.cpp b/modules/regex/regex.cpp
index 8f26d764c42..388e6dfdecc 100644
--- a/modules/regex/regex.cpp
+++ b/modules/regex/regex.cpp
@@ -1340,6 +1340,12 @@ Error RegEx::compile(const String& p_pattern) {
 
 Ref<RegExMatch> RegEx::search(const String& p_text, int p_start, int p_end) const {
 
+	ERR_FAIL_COND_V(!is_valid(), NULL);
+	ERR_FAIL_COND_V(p_start < 0, NULL);
+	ERR_FAIL_COND_V(p_start >= p_text.length(), NULL);
+	ERR_FAIL_COND_V(p_end > p_text.length(), NULL);
+	ERR_FAIL_COND_V(p_end != -1 && p_end < p_start, NULL);
+
 	Ref<RegExMatch> res = memnew(RegExMatch());
 
 	for (int i = 0; i < group_names.size(); ++i) {
@@ -1350,7 +1356,7 @@ Ref<RegExMatch> RegEx::search(const String& p_text, int p_start, int p_end) cons
 
 	res->string = p_text;
 
-	if (p_end < p_start || p_end > p_text.length())
+	if (p_end == -1)
 		p_end = p_text.length();
 
 	RegExSearch s(res, p_end, lookahead_depth);
@@ -1369,18 +1375,45 @@ Ref<RegExMatch> RegEx::search(const String& p_text, int p_start, int p_end) cons
 	return NULL;
 }
 
-String RegEx::sub(const String& p_text, const String& p_template, int p_start, int p_end) const {
+String RegEx::sub(const String& p_text, const String& p_replacement, bool p_all, int p_start, int p_end) const {
 
-	Ref<RegExMatch> m = search(p_text, p_start, p_end);
-	RegExMatch::Group& s = m->captures[0];
-	if (s.start >= 0) {
-		String res = p_text.substr(0, s.start) + m->expand(p_template);
-		int end = s.start + s.length;
-		if (end < p_text.length())
-			res += p_text.substr(end, p_text.length() - end);
-		return res;
+	ERR_FAIL_COND_V(!is_valid(), p_text);
+	ERR_FAIL_COND_V(p_start < 0, p_text);
+	ERR_FAIL_COND_V(p_start >= p_text.length(), p_text);
+	ERR_FAIL_COND_V(p_end > p_text.length(), p_text);
+	ERR_FAIL_COND_V(p_end != -1 && p_end < p_start, p_text);
+
+	String text = p_text;
+	int start = p_start;
+
+	if (p_end == -1)
+		p_end = p_text.length();
+
+	while (start < text.length() && (p_all || start == p_start)) {
+
+		Ref<RegExMatch> m = search(text, start, p_end);
+
+		RegExMatch::Group& s = m->captures[0];
+
+		if (s.start < 0)
+			break;
+
+		String res = text.substr(0, s.start) + m->expand(p_replacement);
+
+		start = res.length();
+
+		if (s.length == 0)
+			++start;
+
+		int sub_end = s.start + s.length;
+		if (sub_end < text.length())
+			res += text.substr(sub_end, text.length() - sub_end);
+
+		p_end += res.length() - text.length();
+
+		text = res;
 	}
-	return p_text;
+	return text;
 }
 
 void RegEx::clear() {
@@ -1456,7 +1489,7 @@ void RegEx::_bind_methods() {
 	ObjectTypeDB::bind_method(_MD("clear"),&RegEx::clear);
 	ObjectTypeDB::bind_method(_MD("compile","pattern"),&RegEx::compile);
 	ObjectTypeDB::bind_method(_MD("search","text","start","end"),&RegEx::search, DEFVAL(0), DEFVAL(-1));
-	ObjectTypeDB::bind_method(_MD("sub","text","template","start","end"),&RegEx::sub, DEFVAL(0), DEFVAL(-1));
+	ObjectTypeDB::bind_method(_MD("sub","text","replacement","all","start","end"),&RegEx::sub, DEFVAL(false), DEFVAL(0), DEFVAL(-1));
 	ObjectTypeDB::bind_method(_MD("is_valid"),&RegEx::is_valid);
 	ObjectTypeDB::bind_method(_MD("get_pattern"),&RegEx::get_pattern);
 	ObjectTypeDB::bind_method(_MD("get_group_count"),&RegEx::get_group_count);
diff --git a/modules/regex/regex.h b/modules/regex/regex.h
index 283368c34fc..8d31b847732 100644
--- a/modules/regex/regex.h
+++ b/modules/regex/regex.h
@@ -97,7 +97,7 @@ public:
 	Error compile(const String& p_pattern);
 
 	Ref<RegExMatch> search(const String& p_text, int p_start = 0, int p_end = -1) const;
-	String sub(const String& p_text, const String& p_template, int p_start = 0, int p_end = -1) const;
+	String sub(const String& p_text, const String& p_replacement, bool p_all = false, int p_start = 0, int p_end = -1) const;
 
 	bool is_valid() const;
 	String get_pattern() const;