Robbie Amell, who last appeared on The Flash Season 3, is returning for a two-episode arc.
Entertainment Weekly broke the news, but there's no telling whether he will be playing Ronnie again or if he will be on board as a new character.
If you watch The Flash online, you know Ronnie died after saving the city from a giant wormhole at the end of The Flash Season 1.
Amell played the Speed Force during The Flash Season 3, and has not been seen or heard from since.
Ronnie was an immediate fan-favorite on the series, with his character in a relationship with Caitlin.
Reuniting the pair would be fun for fans, but nothing is ever that simple in the Arrowverse.
News of Amell's return comes around six weeks after it was revealed the original star Rick Cosnett would be returning for an episode.