At least 48 people were also wounded, including many women and children, the official said, according to state news agency Saba. The celebration, in the city of Ibb, was organised by the Houthis, the Shi'ite Muslim group that controls most of Yemen.
No one claimed responsibility for attack, but similar bombings have been carried out by al Qaeda in the Arabian Peninsula (AQAP), which operates in Yemen and regards Shi'ites as heretics.
Tensions have increased in Yemen since the Houthis captured the capital Sanaa in September and expanded south and west. The Western-allied country, which shares a long border with the world's top oil exporter, Saudi Arabia, had been trying to overcome an al Qaeda threat before the Houthi advance.
The official said the bomber mingled with guests as they arrived at the cultural centre and detonated his suicide belt at the back of the hall.
The official told Saba that all local government officials escaped unharmed, except for the director of the culture department, who suffered serious injuries.
A local resident had earlier said the director general of the Ibb governorate was among the dead.
President Abd-Rabbu Mansour Hadi, in a condolence message to the Ibb governor and families of the victims, condemned "the terrorist and criminal" attack and instructed the government to ensure the wounded receive full medical attention, Saba said.
Residents reported a second explosion occurred outside one of the two hospitals, al-Thawra. But security sources later said that security forces had been firing in the air to disperse residents who had gathered in front of the hospital.