Clark's first major writing credit was "What Lies Beneath" which had a blockbuster cast that included Harrison Ford and Michelle Pfeiffer.
Due to writing such a Blockbuster hit, he was asked personally by Chuck Palahniuk to write "Choke". After he adapted the book into a screenplay, he not only directed but starred in the movie alongside Sam Rockwell and Clark's Father-in-Law Joel Grey.
Clark spent a few years on the script for "Trust Me" which is about a former child actor turn Hollywood agent, that is struggling to keep clients due to a feud with another well known and successful Agent. This ensemble of a cast included Sam Rockwell, Amanda Peet, Saxon Sharbino, Molly Shannon, William H. Macy and Clark's daughter Stella Gregg.
"I'd come out here [LA] and not gotten any work as an actor and I directed that play [Kevin Heelan’s Distant Fires]. One of the agents at my agency said “You know, you should try to make a movie” and I said “Ok, I want to do that, how do I do that?" He said “Write a script that's so good they'll overlook the tremendous liability of having you attached as director [laughing].
[…] And I started writing and I almost got something made, and then they hired me... The first thing I wrote - I wrote as a job for Dreamworks and it became this movie What Lies Beneath, lucky, right out of the gate."
Clark Gregg, WTF Podcast with Marc Maron #705
May 9, 2016
Clark was asked through out the years to direct an episode of Agent's of Shield but said it sounded so daunting. In Season 5, there was a episode that made sense for him to be able to film as well as direct, so he did. He also later directed the first episode of Season 6.
"...at the time they would mention it to me, I couldn’t imagine adding that job, which is prep during one episode, shoot another episode that you’re acting in, and then edit an episode after that. For me, the 22 episodes of Marvel TV, it’s an endurance race. I’ve just been wary of adding anything to the mix like that. And I just couldn’t see how I would do it. Nobody twisted my arm.
I’ve been watching other directors, trying to imagine how I would try to do it, if I would feel comfortable directing the actors I normally work with … and they were very encouraging, really, Chloe, Iain, Elizabeth and Henry, everybody saying, "you should do it." So that really helped push me over.
[...] It was kind of great, because we’re tight. We’re a close bunch, we get along, we have a great crew, we don’t fight, and we take care of each other. I was just worried about how much grief they were going to give me and tease me (laughs). I was right to worry about that, because there were a lot of jokes made and a lot of teasing. It was really fun and it broke the ice".
Clark Gregg, syfy.com
Jan 4, 2018
Clark has stated that, after directing 2 episodes of Marvel's Agents of Shield, he would love to get a chance to direct a MCU movie. With Disney plus coming out at the end of 2019, he would love to sink his teeth in a Marvel movie since he has made 2 mini Marvel movies.
A Breakfast Nook (2010) - a short directed by Clark Gregg. Starring Hannah Louise Miller and Alex Fumero.