The 48-year-old actress and 53-year-old actor, who co-starred in the 2004 movie 13 Going on 30, shared a selfie Tuesday from the set of their film The Adam Project.
The picture shows Garner and Ruffalo smiling for the camera with filming equipment in the background.
"Reconnecting with an old pal. Anyone know where we can get Razzles in Canada?" Ruffalo captioned the post, referencing his 13 Going on 30 character's favorite candy.
Garner posted the same photo on her own account.
"Wishing dust worked! And I got a perfect day with my old pal," she wrote.
Garner and Ruffalo played best friends and love interests Jenna Rink and Matt Flamhaff in 13 Going on 30. The film follows Jenna, a 13-year-old girl who wishes she was 30 years old and is granted her wish through magic wishing dust.
In April, Ruffalo marked the anniversary of the movie's release on Twitter.
"Happy Anniversary to 13 Going on 30 today! Remember what the world was like when Razzles were all the rage? Missing that time," he wrote.
The Adam Project is an upcoming sci-fi film starring Garner, Ruffalo, Ryan Reynolds and Zoe Saldana. The movie is directed by Shawn Levy (Stranger Things), who previously worked with Reynolds on Free Guy.
Reynolds stars as a man who must travel back in time to get help from his 13-year-old self, according to The Hollywood Reporter. Garner and Ruffalo play the parents of Reynolds' character.