A suicide bomber rammed a car containing explosives into the Asasey hotel in the port of Kismayo, and gunmen then stormed the building.
a prominent journalist hodannalayeh, 43, and her husband Farid were among the dead.
Islamist group Al-Shabab has claimed the attack, the worst to hit Kismayo since Al-Shabab was forced out in 2012.
A local politician, three Kenyans, three Tanzanians, two Americans, and one Briton were also killed, authorities say.
Regional politicians and clan elders were inside the hotel discussing a forthcoming regional election when the attack began on Friday. Witnesses said they heard a huge blast before several heavily armed men forced their way in. 

It took 12 hours for authorities to regain control of the hotel.
Regional president Ahmed Mohamed put the death toll at 26 with more than 50 people wounded. Three attackers died in the raid while one was captured.