Venus Williams and Jamie Murray will take on Alicja Rosolska and Michael Venus in the first round of the Wimbledon mixed doubles.
Williams' surprise appearance comes after she requested a late wildcard to play with two-time champion Murray.
The 42-year-old American is a five-time singles champion at the All England Club and won the doubles with her sister Serena on six occasions.
Murray, 36, has also played doubles at Wimbledon with Serena Williams.
His 2007 win came with Jelena Jankovic and he partnered Martina Hingis to victory in the 2017 final.
The Scot will also partner Bruno Soares in the men's doubles as the pair seek a third Grand Slam success together, and a first at Wimbledon.
Murray also has three mixed doubles titles at the US Open to his name, while Venus Williams enjoyed success in the discipline at the Australian Open and French Open in 1998, playing with Justin Gimelstob.
Williams, a mixed doubles finalist with Bob Bryan at Wimbledon in 2006, has been troubled by a leg injury in recent months and has a singles ranking of 570.
Posting about Wimbledon on social media earlier this month, she had said: "No I'm not playing but I'll be watching, I'll be watching Serena."
Poland's Rosolska and New Zealand's Michael Venus are yet to win a Grand Slam mixed doubles title but the latter won the 2017 French Open men's doubles with American Ryan Harrison in 2017.