Dean Kevin O'Brien (born 15 May 1990 in Sandton) is a South African tennis player.

He played college tennis for the Georgia Tech Yellow Jackets.

O'Brien has a career high ATP singles ranking of 507 achieved on 21 April 2014.

Playing for the South Africa in Davis Cup, O'Brien has a W/L record of 1–2.

This biographical article relating to South African tennis is a stub.