The 45-year-old "Better Off Ted" actor will be seen playing Mark Meadows, Donna Paulson's ex-boyfriend in two episodes, according to The Hollywood Reporter.
"We have discussed Jay for many roles over the years because our casting director, Bonnie Zane, knows I'm a huge fan of his from 'Better Off Ted' and other things. Often he was unavailable. A few months ago he was pitched for the role of Tommy Bratton, but we ended up going with Al Sapienza. A few weeks later we were writing the role of Mark Meadows and that was perfect.
The role brings Harrington back to USA, where he featured in the 2014 short-lived legal comedy "Benched".
"Suits" is currently in its seventh season.