Around 200 people turned up to the rally organised by Unite Against Fascism Scotland on Tuesday evening.
The event was in response to a hate crime in which a flaming object was hurled at the mosque in the early hours of Sunday.
The front door of the building in Potterrow was damaged in the attack but no one was injured.
Speakers included members of the Muslim Women's Association of Edinburgh as well as local politicians.
Police are still appealing for witnesses to get in touch by calling 101.