It's one of the most highly-anticipated films of 2019, and its stars were excited to celebrate which at a huge premiere in Los Angeles.
And the star-studded cast of Avengers: Endgame didn't disappoint their diehard fans by providing a behind-the-scenes look at the ritzy event — from their plush hotel rooms to the purple carpet they arrived on.
The famous actors took to social media to share the events of the day — from meeting with fans, waiting for security, and a peek inside the lavish after-party.
One image saw Zoe Saldana give fans an insight from her car as she waited to get through the intense security outside the event's entrance.
The Guardians Of The Galaxy star, looked striking in her pleated full-length magenta gown, but the face she pulled implied she was less than impressed with the wait.
Robert Downey Jr, 54, posted a pic of him resting on his electric supercar, mimicking his character Iron Man's signature pose.
Brie Larson took to Instagram to thank car manufacturer Audi for providing her with the ride and posed in front of it.
The Captain Marvel actor also showed her affection for co-star Tessa Thompson, as she gave her a kiss on the cheek while a security guard look on and smiled.
The Thor: Ragnarok star chimed in: "He looks how I feel."
Many of the stars met with the fans who waited outside the premiere for a glimpse into the action.
Benedict Cumberbatch excitedly posed for a selfie with one fan, while Jeremy Renner followed suit — sticking his tongue out while taking a snap.
Vin Diesel also seemed to enjoy his time at the premiere, beaming when he saw a fan dressed as his character Groot.
Pop star Miley Cyrus also shared a fun glimpse of her ride into the premiere with her husband Liam Hemsworth, as they stepped out in support of his brother and Thor star, Chris.
The singer, 26, stunned on the red carpet in a black velvet Yves Saint Laurent dress.
Ariana Grande's brother Frankie looked like he was having a great time at the party, looking animated as he took selfies with a number of stars.
Avengers: Endgame follows on from Infinity War, which featured an epic, and traumatising, twist, which saw half of all life in the universe disintegrate after the evil demigod collected all six infinity stones on the Infinity Gauntlet.