Sarra Lajnef (born September 5, 1989, in Tunis) is a Tunisian swimmer.At the 2011 All-Africa Games, Sarra won three silver medals in 400 m freestyle swimming, 100 m and 200 m Breaststroke.
At the 2012 Summer Olympics, she competed in the Women's 200 metre breaststroke, finishing in 31st place overall in the heats, failing to qualify for the semifinals.