This list will provide an overview of different ways to watch, or catch up on, the Avengers film franchise up to and including Avengers: Endgame. We'll stop at Endgame, since the next Avengers film, currently titled Avengers 5, isn't out until 2026, and there's no way to know for sure what elements from the other films will be important.
How to Watch Every Marvel Movie in Chronological Order
It’s easy to confuse “The Avengers” with “Marvel movies” in general, since the franchise tends to tie all of its films together. Sometimes it’s just a scene that pops up after the credits, but there are still a fair number of titles that tie together, even without the superteam name in the title.
If you're only interested in the primary Avengers films, their release and chronological order are the same:
The thing about The Avengers as a film series is that there are a lot of semi-standalone films that tie into it, especially when it comes to introducing and establishing various major characters. If you want all the important context up to this point, you're going to have to add a lot more titles to the list.