We may never see Robert Downey Jr. star in another solo Iron Man film, but he's not done with the MCU. Ever since Kevin Feige confirmed that other MCU characters will appear in Spider-Man: Homecoming, rumors of RDJ appearing alongside Tom Holland have circulated the webs.
Now, The Hollywood Reporter has confirmed that the Iron Man actor will be in the film, but Marvel hasn't released details how Tony Stark will fit in Homecoming's story. While most of the MCU actors are still under multiple-movie contracts, Downey was not —he's only under contract for future Avengers movies through the end of Infinity War. They had to pay the actor extra to be a part of Civil War, and it would seem that Marvel made a similar deal.
According to Civil War's official character descriptions, Spider-Man was personally recruited by Iron Man to join the fight, so Stark will most likely continue his tutelage with Tom Holland's Peter Parker. However, official plot details haven't been revealed yet.
Check out RDJ's response when he was asked if he would appear in the film,
Spider-Man: Homecoming is set to release in theaters on July 7, 2017.