Ivan Kaye made his theater debut in 1980 at Sadler's Wells Theatre (London) as Willie Wonka in a stage version of Charlie and the Chocolate Factory. More theatre roles followed throughout the 1980s and 1990s, e.g. at the Royal National Theatre and the Piccadilly Theatre (The Rocky Horror Show).

In 1990, he started his television career by guest starring in the crime shows The Paradise Club and The Bill. In 1992 he played the leading part Sam Sterne in ITV's crime show Sam Saturday. Since then he has played almost 40 roles in television and, starting in 2004, in movies (Layer Cake, Control).

Earlier internationally known roles include Reuben Starkadder in the television film Cold Comfort Farm (1995) and Adonija in the German-Italian-French co-production Solomon (1997). Mainly in the United Kingdom Ivan Kaye is also known for his characters Dr. Johnathon Leroy in 27 episodes of the soap opera EastEnders in 2003-2004 and the herdsman Bryan in all of the episodes of the 4 Series television sitcom The Green Green Grass (2005-2009).

By supporting the Hounslow Urban Farm and the animal home The Mayhew Ivan Kaye stands up for the protection of animals and the environment. He also supports the campaign "Justice for Andrew Jones" which aims at bringing the killers of a teenager to court who was killed in 2003 in Liverpool on the street.

Ivan Kaye's roles in recent international productions include drug baron Polo Yakur in Assassination Games (2011), the Duke of Milan Ludovico Sforza in The Borgias (2011-2013), Joshua Collins, father of the main character Barnabas Collins (Johnny Depp) in Dark Shadows (2012), famous Viking warrior Ivar the Boneless in Hammer of the Gods (2013), pub landlord Mick Sturrock in BBC One's crime show The Coroner (2015-2016) and the Saxon King Aelle of Northumbria in History channel's period drama Vikings (2013-2017).

Aside from his villain roles as cold-blooded Polo Yakur and unscrupulous Duke Ludovico it is mainly his portrayal of King Aelle - in Vikings the deadly enemy and nemesis of the legendary hero of the show Ragnar Lothbrok (Travis Fimmel) - that has recently shaped Ivan Kaye's international profile. In his Twitter bio he describes himself as "Villain for Hire". His performances in the second part of Season 4 of Vikings have met with increased interest as his character King Aelle is of pivotal importance in the scenes of Ragnar's death and at the centre of attention during his own execution through the blood eagle torture inflicted by Ragnar's sons in revenge for the death of their father. In an interview on his character King Aelle in September 2017 Ivan Kaye has contested the assessment of this antagonist as a villain - an assessment that had already been subject to disputes between parts of the audience.