The duo, who appeared together in four episodes of the NBC comedy series in 2010, were spotted spending time together in New York City on Monday.
The duo, who appeared together in four episodes of the NBC comedy series in 2010, were photographed strolling in New York City and stopping by the actor’s apartment.
“They met to discuss a potential film project,” a source tells PEOPLE.
The Tropic Thunder writer, 46, guest starred on Parks and Recreation as Justin Anderson, the love interest of Leslie Knope, played by Amy Poehler. Plaza appeared in all seven seasons of the popular sitcom as fan-favorite April Ludgate. Both are also accomplished comedy writers.
Theroux has been sticking to his normal routine since announcing his split from Jennifer Aniston last month, a source previously told PEOPLE.
“He’s just doing his thing,” a source said. “He eats at the same time, goes to the same places, hangs with the same people.”
Earlier in the weekend, Plaza, 33, met up with some of her other costars from the show for the March For Our Lives protest in Washington D.C. on Saturday. The actress posed for a photo alongside Parks and Recreation alums like Natalie Morales, Paul Rudd, Adam Scott and Billy Eichner.
Meanwhile, Theroux “has moved on with his life in N.Y.C.,” since his split from Aniston, a source recently told PEOPLE. Earlier in March, he was in Paris for Fashion Week, where he attended the Louis Vuitton womenswear show and spent time reenacting a Bachelor rose ceremony with longtime friend Carlos Quirarte.
Before leaving for Paris, he was spotted in Austin, Texas, where he made a visit to a dog shelter — and posted an adorable photo on Instagram.
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On Feb. 15, Aniston and Theroux announced that they had split after two and a half years of marriage and seven years as a couple.
“In an effort to reduce any further speculation, we have decided to announce our separation,” the former couple said in a joint statement. “This decision was mutual and lovingly made at the end of last year. We are two best friends who have decided to part ways as a couple, but look forward to continuing our cherished friendship.”
As for Plaza’s love life, the actress was most recently linked to Jeff Baena, who directed her in 2017’s The Little Hours, in which she played a 14th century nun alongside Alison Brie. Baena and Plaza first worked together on his 2014 zombie comedy Life After Beth.