The actor will join the cast as ex-convict and gator farm owner Dale Crowe, Jr., the smart, ruthless and charismatic patriarch of a Florida crime family who will face off against Raylan Givens (Timothy Olyphant) in the upcoming fifth season.
The character is related to Boyd Crowder's (Walton Goggins) dim-witted friend Dewey Crowe (Damon Herriman).
The Crowes will likely draw comparisons to the Bennett clan from the second season, which was headed by Mags, played by Emmy-winner Margo Martindale.
"Justified" showrunner Graham Yost had recently expressed a desire to integrate the Crowes and more of Elmore Leonard's characters into Season 5.
View slideshow: Meet the new "Justified" cast members for Season 5
“Before he had his stroke we were thinking, you know, we’re headed to end of the series, we’ve maybe got two seasons left – so we wanted to bring in the Crowe family which is a big part of his world," Yost told Deadline.com shortly after the author's death. "We’ve got Dewey Crowe on the show but there are other Crowes that populated his books and we thought it would be fun to focus on that.”
Rapaport's TV credits include "Friends," "Boston Public," "My Name is Earl," "Prison Break," and "The Mob Doctor." He was also cast in CBS' new sitcom "The Millers," which co-stars Martindale, but was later replaced by Nelson Franklin ("New Girl").
"Justified" returns to FX for Season 5 in early 2014.