Welsh Reserve soldiers fired the guns outside City Hall on Saturday as the Duke of Edinburgh turns 96.
The event was organised by 160th Infantry Brigade and Headquarters Wales, of Brecon, and hosted by 104 Regiment Royal Artillery, from Newport.
Another gun salute will be held in Cardiff Bay, outside the Pierhead building, to celebrate the Queen's official birthday next Saturday.
A gun salute has been fired in Cardiff to mark Prince Philip's birthday.