diff --git a/osu.Game.Tests/Visual/Online/TestSceneChatOverlay.cs b/osu.Game.Tests/Visual/Online/TestSceneChatOverlay.cs
index 7cfca31167..609e637914 100644
--- a/osu.Game.Tests/Visual/Online/TestSceneChatOverlay.cs
+++ b/osu.Game.Tests/Visual/Online/TestSceneChatOverlay.cs
@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
@@ -85,6 +86,22 @@ namespace osu.Game.Tests.Visual.Online
                         case JoinChannelRequest joinChannel:
                             joinChannel.TriggerSuccess();
                             return true;
+
+                        case GetUserRequest getUser:
+                            if (getUser.Lookup.Equals("some body", StringComparison.OrdinalIgnoreCase))
+                            {
+                                getUser.TriggerSuccess(new User
+                                {
+                                    Username = "some body",
+                                    Id = 1,
+                                });
+                            }
+                            else
+                            {
+                                getUser.TriggerFailure(new Exception());
+                            }
+
+                            return true;
                     }
 
                     return false;
@@ -322,6 +339,27 @@ namespace osu.Game.Tests.Visual.Online
             AddAssert("Current channel is channel 1", () => currentChannel == channel1);
         }
 
+        [Test]
+        public void TestChatCommand()
+        {
+            AddStep("Join channel 1", () => channelManager.JoinChannel(channel1));
+            AddStep("Select channel 1", () => clickDrawable(chatOverlay.TabMap[channel1]));
+
+            AddStep("Open chat with user", () => channelManager.PostCommand("chat some body"));
+            AddAssert("PM channel is selected", () =>
+                channelManager.CurrentChannel.Value.Type == ChannelType.PM && channelManager.CurrentChannel.Value.Users.Single().Username == "some body");
+
+            AddStep("Open chat with non-existent user", () => channelManager.PostCommand("chat nobody"));
+            AddAssert("Last message is error", () => channelManager.CurrentChannel.Value.Messages.Last() is ErrorMessage);
+
+            // Make sure no unnecessary requests are made when the PM channel is already open.
+            AddStep("Select channel 1", () => clickDrawable(chatOverlay.TabMap[channel1]));
+            AddStep("Unregister request handling", () => ((DummyAPIAccess)API).HandleRequest = null);
+            AddStep("Open chat with user", () => channelManager.PostCommand("chat some body"));
+            AddAssert("PM channel is selected", () =>
+                channelManager.CurrentChannel.Value.Type == ChannelType.PM && channelManager.CurrentChannel.Value.Users.Single().Username == "some body");
+        }
+
         private void pressChannelHotkey(int number)
         {
             var channelKey = Key.Number0 + number;
diff --git a/osu.Game/Online/API/Requests/GetUserRequest.cs b/osu.Game/Online/API/Requests/GetUserRequest.cs
index e49c4ab298..730e4e02ed 100644
--- a/osu.Game/Online/API/Requests/GetUserRequest.cs
+++ b/osu.Game/Online/API/Requests/GetUserRequest.cs
@@ -8,7 +8,7 @@ namespace osu.Game.Online.API.Requests
 {
     public class GetUserRequest : APIRequest<User>
     {
-        private readonly string lookup;
+        public readonly string Lookup;
         public readonly RulesetInfo Ruleset;
         private readonly LookupType lookupType;
 
@@ -26,7 +26,7 @@ namespace osu.Game.Online.API.Requests
         /// <param name="ruleset">The ruleset to get the user's info for.</param>
         public GetUserRequest(long? userId = null, RulesetInfo ruleset = null)
         {
-            lookup = userId.ToString();
+            Lookup = userId.ToString();
             lookupType = LookupType.Id;
             Ruleset = ruleset;
         }
@@ -38,12 +38,12 @@ namespace osu.Game.Online.API.Requests
         /// <param name="ruleset">The ruleset to get the user's info for.</param>
         public GetUserRequest(string username = null, RulesetInfo ruleset = null)
         {
-            lookup = username;
+            Lookup = username;
             lookupType = LookupType.Username;
             Ruleset = ruleset;
         }
 
-        protected override string Target => lookup != null ? $@"users/{lookup}/{Ruleset?.ShortName}?k={lookupType.ToString().ToLower()}" : $@"me/{Ruleset?.ShortName}";
+        protected override string Target => Lookup != null ? $@"users/{Lookup}/{Ruleset?.ShortName}?key={lookupType.ToString().ToLower()}" : $@"me/{Ruleset?.ShortName}";
 
         private enum LookupType
         {
diff --git a/osu.Game/Online/Chat/ChannelManager.cs b/osu.Game/Online/Chat/ChannelManager.cs
index 1937019ef6..47d5955fb0 100644
--- a/osu.Game/Online/Chat/ChannelManager.cs
+++ b/osu.Game/Online/Chat/ChannelManager.cs
@@ -256,8 +256,36 @@ namespace osu.Game.Online.Chat
                     JoinChannel(channel);
                     break;
 
+                case "chat":
+                case "msg":
+                case "query":
+                    if (string.IsNullOrWhiteSpace(content))
+                    {
+                        target.AddNewMessages(new ErrorMessage($"Usage: /{command} [user]"));
+                        break;
+                    }
+
+                    // Check if the user has joined the requested channel already.
+                    // This uses the channel name for comparison as the PM user's username is unavailable after a restart.
+                    var privateChannel = JoinedChannels.FirstOrDefault(
+                        c => c.Type == ChannelType.PM && c.Users.Count == 1 && c.Name.Equals(content, StringComparison.OrdinalIgnoreCase));
+
+                    if (privateChannel != null)
+                    {
+                        CurrentChannel.Value = privateChannel;
+                        break;
+                    }
+
+                    var request = new GetUserRequest(content);
+                    request.Success += OpenPrivateChannel;
+                    request.Failure += e => target.AddNewMessages(
+                        new ErrorMessage(e.InnerException?.Message == @"NotFound" ? $"User '{content}' was not found." : $"Could not fetch user '{content}'."));
+
+                    api.Queue(request);
+                    break;
+
                 case "help":
-                    target.AddNewMessages(new InfoMessage("Supported commands: /help, /me [action], /join [channel], /np"));
+                    target.AddNewMessages(new InfoMessage("Supported commands: /help, /me [action], /join [channel], /chat [user], /np"));
                     break;
 
                 default: