Darren Boyd, who stars as MI5 agent Tim in the sitcom, confirmed the news on Twitter this morning.
Boyd told fans: "I have handed in my badge and gun."
Spy also starred Robert Lindsay, Mathew Baynton, Rebekah Staton and Jude Wright as Tim's son. Boyd won a BAFTA for his performance in the show.
The final episode was a Christmas special in 2012.
ABC in America is currently remaking Spy with Rob Corddry in Darren Boyd's role as Tim and The Hangover star Ken Jeong taking on Lindsay's role as the Examiner.
Watch our interview with the cast of Spy below: