The US record holder, suspended after a 2013 positive test for an anabolic steroid, will race American rival Justin Gatlin, who served a four-year doping ban, and Frenchman Jimmy Vicaut over 100 metres at the July 3 meeting.
"Lausanne has always been one of my favourite meets, and I'm thrilled to have it be my opening meet," said Gay, noting he had been in training for several months.
The US Anti-Doping Agency (USADA) said last month that Gay, the world's joint second fastest man, had accepted a one-year suspension backdated to June 23, 2013 after offering what it termed substantial assistance in his case.
He also returned his silver medal from the 4x100 metres relay at the 2012 London Olympics.
The controversial decision meant Gay would be eligible to compete from June 23.
Normally athletes receive a two-year suspension for their first doping offense, but under anti-doping rules the ban can be reduced for substantial cooperation.
- Sports & Recreation
- Addiction & Substance Abuse
- Justin Gatlin