Hargitay, who still stars on the NBC series, shared a slideshow of photos Sunday on Instagram with Meloni, who left the show after Season 12.
Hargitay and Meloni were all smiles as they enjoyed a meal together. The pair wore printed shirts, with Hargitay in a floral design and Meloni in paisley.
"Sunday night dinner...." Hargitay captioned the post.
Hargitay plays Lt. Det. Olivia Benson on Law & Order: SVU, which returns for its 21st season Sept. 26. Meloni portrayed Det. Elliot Stabler in the show's first 12 seasons.
Law & Order: SVU showrunner Warren Leight recently told E! News he hopes Meloni will return as Stabler at some point.
"As long as the show is running, I feel like we will -- someday, I would hope to see him again," Leight said. "I don't know how, I don't know when, but ... the fans and Benson and Stabler are owed that."