Ojinnaka will miss the first regular-season game at Pittsburgh on Sept. 12. The league announced the suspension on Thursday, citing its personal conduct policy.
Police in suburban Gwinnett County said Ojinnaka was arrested in May 2009 on a simple battery charge after his wife confronted him over his contact with a female friend on the social networking site Facebook. He was accused of tossing her down some stairs and throwing her out of the house.
Ojinnaka started five games last season and is expected to be a backup on the Falcons' offensive line.