diff --git a/src/main/java/org/qortal/api/resource/ChatResource.java b/src/main/java/org/qortal/api/resource/ChatResource.java
index 2601e938..150b6f63 100644
--- a/src/main/java/org/qortal/api/resource/ChatResource.java
+++ b/src/main/java/org/qortal/api/resource/ChatResource.java
@@ -72,6 +72,7 @@ public class ChatResource {
 			@QueryParam("reference") String reference,
 			@QueryParam("chatreference") String chatReference,
 			@QueryParam("haschatreference") Boolean hasChatReference,
+			@QueryParam("sender") String sender,
 			@Parameter(ref = "limit") @QueryParam("limit") Integer limit,
 			@Parameter(ref = "offset") @QueryParam("offset") Integer offset,
 			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse) {
@@ -107,6 +108,7 @@ public class ChatResource {
 					chatReferenceBytes,
 					hasChatReference,
 					involvingAddresses,
+					sender,
 					limit, offset, reverse);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
diff --git a/src/main/java/org/qortal/api/websocket/ChatMessagesWebSocket.java b/src/main/java/org/qortal/api/websocket/ChatMessagesWebSocket.java
index 76ed936c..c6d7aaed 100644
--- a/src/main/java/org/qortal/api/websocket/ChatMessagesWebSocket.java
+++ b/src/main/java/org/qortal/api/websocket/ChatMessagesWebSocket.java
@@ -49,6 +49,7 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 						null,
 						null,
 						null,
+						null,
 						null, null, null);
 
 				sendMessages(session, chatMessages);
@@ -79,6 +80,7 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 					null,
 					null,
 					involvingAddresses,
+					null,
 					null, null, null);
 
 			sendMessages(session, chatMessages);
diff --git a/src/main/java/org/qortal/repository/ChatRepository.java b/src/main/java/org/qortal/repository/ChatRepository.java
index c4541907..34ad77dd 100644
--- a/src/main/java/org/qortal/repository/ChatRepository.java
+++ b/src/main/java/org/qortal/repository/ChatRepository.java
@@ -15,7 +15,7 @@ public interface ChatRepository {
 	 */
 	public List<ChatMessage> getMessagesMatchingCriteria(Long before, Long after,
 			Integer txGroupId, byte[] reference, byte[] chatReferenceBytes, Boolean hasChatReference,
-			List<String> involving, Integer limit, Integer offset, Boolean reverse) throws DataException;
+			List<String> involving, String senderAddress, Integer limit, Integer offset, Boolean reverse) throws DataException;
 
 	public ChatMessage toChatMessage(ChatTransactionData chatTransactionData) throws DataException;
 
diff --git a/src/main/java/org/qortal/repository/hsqldb/HSQLDBChatRepository.java b/src/main/java/org/qortal/repository/hsqldb/HSQLDBChatRepository.java
index a995a0b3..55467d87 100644
--- a/src/main/java/org/qortal/repository/hsqldb/HSQLDBChatRepository.java
+++ b/src/main/java/org/qortal/repository/hsqldb/HSQLDBChatRepository.java
@@ -24,7 +24,7 @@ public class HSQLDBChatRepository implements ChatRepository {
 
 	@Override
 	public List<ChatMessage> getMessagesMatchingCriteria(Long before, Long after, Integer txGroupId, byte[] referenceBytes,
-			byte[] chatReferenceBytes, Boolean hasChatReference, List<String> involving,
+			byte[] chatReferenceBytes, Boolean hasChatReference, List<String> involving, String senderAddress,
 			Integer limit, Integer offset, Boolean reverse) throws DataException {
 		// Check args meet expectations
 		if ((txGroupId != null && involving != null && !involving.isEmpty())
@@ -74,6 +74,11 @@ public class HSQLDBChatRepository implements ChatRepository {
 			whereClauses.add("chat_reference IS NULL");
 		}
 
+		if (senderAddress != null) {
+			whereClauses.add("sender = ?");
+			bindParams.add(senderAddress);
+		}
+
 		if (txGroupId != null) {
 			whereClauses.add("tx_group_id = " + txGroupId); // int safe to use literally
 			whereClauses.add("recipient IS NULL");