Guardians of the Galaxy Vol. 2 director James Gunn has confirmed on Facebook that the third Guardians film will debut in 2020 - in his words "in a little under three years."
Gunn also confirmed that the film will be titled Guardians of the Galaxy Vol. 3, "unless something changes."
Additionally, Gunn addressed the idea of directing Star Wars: Episode IX in the wake of director Colin Trevorrow's departure from the film, saying, "I would not and could not. Right now I'm doing Guardians 3, producing a new film with David Yarovesky, and developing Starsky & Hutch for Amazon.com. My plate is full for three years."
Marvel has already secured these 2020 dates for as-yet unnamed films: May 1, August 7, and November 6. Given Gunn's "a little under three years" comment, May 1, 2020 seems like a safe bet.