Message moderation is described herein. In an example, a message posted to a virtual space of a communication platform can be flagged for review by a reviewer (e.g., an administrator or other user permissioned to review messages). In some examples, such a reviewer can review a flagged message and determine one or more actions to be performed. Such actions can include removing the message from presentation via the communication platform, modifying presentation of the message via a user interface of the communication platform, replying to the message (e.g., to suggest taking the conversation offline or to another virtual space), disabling interaction with the message, and/or the like. Message moderation, as described herein, can streamline resolution of conversations that become out of hand and/or off topic.