Boyd joins previously announced Mark Patterson and Matt Bell behind the wheel of the No. 3 Ligier JS P3.
The 25-year-old British driver finished third in the 2011 US F2000 National Championship and is a two-times Formula Ford Festival winner. In 2009 Boyd raced in the British Formula 3 championship.
“I’m absolutely delighted to join United Autosports and I’m very grateful for the opportunity,” said Boyd.
“I’ve always followed the ELMS and wanted to be a part of it, especially in prototypes.”
“I’ve known Richard for years and now to be able to work with him and United Autosports is fantastic. Massive thanks for all the people who have helped make this happen.”
“We are really pleased Wayne is joining the team for our debut in the ELMS,” added team owner Richard Dean.
“I have been following Wayne’s career for a number of years now and he is a very impressive driver and will bring exactly what we need to the team.”
“I’m thrilled to have finalised all six of our drivers now and I think we have a really strong line up. I can’t wait to get started.”