Every Batman movie in order
To watch the Batman movies in order, start with Batman, then Batman Returns and Batman Forever. That's 11 out so far, about 28 hours, ending with The Batman.
Batman has been rebooted again and again, so there isn't one story. These are the live-action films in the order they came out, grouped by who plays him: Michael Keaton, Val Kilmer and George Clooney, Christian Bale, Ben Affleck and Robert Pattinson.
Each group stands on its own, so you can start at any of them.
Updated
The Batman movies in order
Batman
Michael Keaton's Batman faces Jack Nicholson's Joker.
Batman Returns
Keaton again, against the Penguin and Catwoman.
Batman Forever
Val Kilmer takes over, and Robin arrives.
Batman & Robin
George Clooney's only outing.
Batman Begins
Christopher Nolan starts again with Christian Bale.
The Dark Knight
Heath Ledger's Joker.
The Dark Knight Rises
The end of Nolan's trilogy.
Batman v Superman: Dawn of Justice
Ben Affleck's older Batman takes on Superman.
Zack Snyder's Justice League
Batman gathers the Justice League.
The Flash
Affleck's last appearance, and Keaton's return.
The Batman
Robert Pattinson's detective Batman, separate from every film before it.
Questions
What order should I watch the Batman movies in?
Start with Batman, then Batman Returns and Batman Forever, and follow the list above: 11 in all, ending with The Batman.
How long does it take to watch all of the Batman movies?
About 28 hours for the 11 out so far.
Are the Batman movies connected?
Only within each group. Keaton's two films lead into Kilmer's and Clooney's, Nolan's trilogy is its own story, Affleck's Batman is part of the DCEU, and The Batman is separate again.
Which Batman movies should I watch first?
The Dark Knight trilogy is the most popular place to start. Batman Begins needs nothing before it.
Watch the Batman movies with Chronologica
Make a plan of just the Batman movies, mark them off as you go and always know what's next. No account needed.