Pratt, who portrays Star-Lord in the Marvel cinematic universe, was all smiles alongside Schwarzenegger on Monday as the pair posed together.
The actor wore a black suit with a white undershirt and a checkered tie while Schwarzenegger donned a black and silver leopard-printed dress by Monique Lhuillier, People magazine reported.
Pratt was previously married to actress Anna Faris for eight years before they called it quits in August 2017. Pratt and Faris are co-parents to their 6-year-old son Jack.
Avengers: Endgame is set to arrive in theaters on Friday.
Other cast members from the superhero epic, including Robert Downey Jr. (Iron Man), Chris Evans (Captain America), Chris Hemsworth (Thor), Mark Ruffalo (Hulk), Brie Larson (Captain Marvel), Don Cheadle (War Machine), Paul Rudd (Ant-Man), Karen Gillan (Nebula), Danai Gurira (Okoye) and Jeremy Renner (Hawkeye), sang a remix of Billy Joel's "We Didn't Start the Fire" with Jimmy Fallon on The Tonight Show which recapped the entire Marvel cinematic universe leading up to Endgame.