This shopping center was built in the mid 70’s and was first anchored by Zayre and Shop & Save supermarket. In the mid 80’s, Ames opened at the nearby Seabrook Plaza. When Ames acquired Zayre, the company closed the Southgate Plaza store in 1990. Market Basket moved into the former Zayre and Tjmaxx opened in the former Shop & Save. Poore Simon's moved out in 1991 followed by Fayva which closed in the mid 1990's. The exterior of the plaza has been renovated at some point. CVS closed its pharmacy at Southgate to relocate in a free-standing building down the road.

The plaza recently changed its giant pylon sign and replaced it with a more modern and smaller one. In 2008, the owners of the Plaza proposed to add more retail space (two stores, total of 25,000 sq.ft.) and expand the supermarket. A drive-thru pharmacy was also planned. The entrance of the plaza has been realigned to fit with the entrance to a new Kohl's and Lowe’s across the street.

In 2012, the plaza announced it was expanding. See article here. Also in 2012 Fashion Bug announced it would close all of its stores including the Seabrook location. Olympia Sports relocated from the Seacoast Shopping center and the NH Liquor store outlet relocated there from the Seabrook Plaza.