Sergiu Postica (born May 17, 1985) is a Moldovan former swimmer, who specialized in breaststroke events.
He is a two-time Olympian (2004 and 2008) and a multiple-time Moldovan record holder in the 100 and 200 m breaststroke.
Postica made his first Moldovan team at the 2004 Summer Olympics in Athens, where he competed in the men's 200 m breaststroke.
He edged out Kyrgyzstan's Anton Kramarenko to take a sixth spot and forty-fifth overall by more than a second in 2:27.21.At the 2008 Summer Olympics in Beijing, Postica qualified for the men's 100 m breaststroke by eclipsing a FINA B-standard entry time of 1:03.71 from the Russian Open Championships in Saint Petersburg.
He challenged five other swimmers on the second heat, including two-time Olympian Nguyen Huu Viet of Vietnam.
Postica raced to second place by 0.11 of a second behind Panama's Edgar Crespo in 1:03.83.
Postica failed to advance into the semifinals, as he placed fifty-fourth overall on the first night of preliminaries.