Wolff will also drive on the opening day of the post-race tests in Spain and Austria, as well as completing an "extensive programme of work" in the Williams simulator.
“Our focus this year is to build on the success of 2014 - I've been training hard all winter and I am physically in the best shape I've ever been, so I am ready for the season ahead," said Wolff, who last year became the first female in two decades to compete in a Grand Prix session.
“As official test driver I will have additional time in the FW37 and by correlating this with my work in the simulator, the team can ensure we are getting the best from the car and check how updates are performing.
“All of us drivers on the Williams roster have been working closely together on this and we are ready to give everything we can to the 2015 season."
Williams' deputy team principal Claire Williams added: “Last season Susie impressed with her performances during FP1 at Silverstone and Hockenheim and we were keen to give her another chance to test in 2015.
“She knew the FW36 well and with the FW37 being a gradual evolution, we were keen to utilise this knowledge and get her in the car to help assess and validate the approaches we have taken."
Wolff has already driven Williams' 2015 car, the FW37, on the opening day of the second pre-season test at Barcelona.