Here's How 'Louie' Lands Such Amazing Guest Stars

FX's "Louie" - starring comedian Louis C.K. - frequently has A-list celebrities like Jerry Seinfeld, Jeremy Renner, Ricky Gervais, and tons of comedians guest-starring in bit and larger roles on the show.

Often it's as easy as Louis calling up his friends from the Comedy Cellar to come down to set, "Louie" casting director Gayle Keller tells Business Insider.

"I don't think I've ever auditioned any of his comedian friends," says Keller. "He will just say, 'Hey Gayle, I want Todd Barry on the show,' or 'This role is going to be played by Todd Berry,' or 'Robert Kelly is going to play my brother,' or 'Sarah Silverman is going to be on the show.'"

"His knowledge of the comedians is even more vast than mine," says Keller. "If I bring up a comedian to him, he might say 'Oh he's not right for this' or 'He's right,' so I'll come up with my own ideas, but he has such a knowledge of the comedians, differently than I do since many of them are his close friends, that he'll just offer them the roles."

Keller says that Louis - who serves as writer, director, editor, and star of the show - will both write roles with certain comedian friends in mind and other times fill roles with comedians who he thinks would be a good fit.

"Like Doug Stanhope, who was in season three, he's a stand-up, and Louis wrote a particular role for Doug," says Keller. "But then there'll be other times where he'll say 'I want a comedian in this role' and ask me for ideas."

This season Oscar-nominated "Hurt Locker" actor Jeremy Renner appeared in two episodes playing a drug dealer who sells to a young Louie during flashback scenes.

Keller says Renner was an easy get.

"Both Louis and Jeremy were in 'American Hustle' and when Louis wrote this piece, he was like, 'Jeremy Renner would be so amazing in this role,' so we reached out to his manager, got him the script, and he said he would do it."

When Jerry Seinfeld appeared on season 4 as a jerkier version of himself, Keller says it was because the two "are good friends."

Oscar-winning 81-year-old actress Ellen Burstyn - who played Louie's older Hungarian neighbor, Evanka - wasn't as easy of a casting.

"Ellen Burnstyn was interesting," Keller reveals. "That part was written in a very different way. They wanted an older woman who was Hungarian and we auditioned a lot of wonderful actors in New York, but Louis wasn't sure if he had found her yet. So I suggested we think of well known actors we could just offer the role to, and I mentioned Ellen Burstyn [who Keller cast in 2000's "Requiem for a Dream"] and her agent said it was something she could be interested in."

"I told Louis we should just offer her the part and it changed a little bit about what he envisioned for the role, but he was always a huge fan of hers and she was fantastic so he said, 'Let's do it. Let's go for it.' And she said yes."

But perfecting a Hungarian accent wasn't always easy for Burstyn.

"We kind of made it work for her with the Hungarian and she helped us make that character because it's a little bit different from the way it was originally written," explains Keller. "It's a woman who is a little more old world in a way. Ellen brought so much life to it and she's so vivacious and so beautiful that she elevated that character and in a different way."

As for whether any of this season's guest stars will be back next season, Keller says, "Who knows? I haven't seen any scripts for next season."

But Keller is always keeping up with Louis, scouting comedians at local New York City clubs.

"I love comedy clubs, I love going to sketch, I love going to UCB, and the Pit," Keller says of where she finds new talent. "I try to see as many people as possible, I'm aware of all the 'SNL' people, and I try to get to know as many comics as possible because that's the show. But anyone I bring up, he already knows who they are."