The 12-month trial will include the northern beaches at Sandgate, Shorncliffe and Nudgee Beach, as well as Manly in the south.
It follows years of petitions and requests to council as it is currently illegal to let dogs off leash on all Brisbane beaches.
Lord Mayor Adrian Schrinner said the designated dog off-leash areas had been selected to ensure dog owners could have a great time without disturbing migratory shorebirds, which visit Moreton Bay every year between September and April.