Hemsworth, 38, who plays the God of Thunder, walked the red carpet with wife Elsa Pataky, 45, and their twins Sasha and Tristan, 8.
Pataky, who starred on marie claire Australia's June cover, shined in a cut-out Halston dress, pairing it with Tom Ford shoes and a Bulgari Serpenti Viper necklace and rings.
Waititi also brought his daughters, Matewa Kiritapu and Te Hinekahu, along to the star-studded premiere.
"That's nepotism for you," Waititi joked to the crowd at Sydney's Entertainment Quarter.
Waititi shares his daughters with his ex wife, New Zealand filmmaker Chelsea Winstanley. His current girlfriend (and rumoured fiancée) Rita Ora was not in attendance.
Thor: Love and Thunder is the fourth film in the Thor series, following Thor as he attempts to find inner peace in the events following Avengers: Endgame — but ends up returning to battle instead. He also needs to content with ex girlfriend (and astrophysicist) Jane Foster (Natalie Portman), who has wilded his former weapon to become the Mighty Thor.
At the premiere, Hemsworth and Waititi described Love and Thunder as "a rom-com" for the Marvel cinematic universe.
“We wanted to make something that’s entertaining, energetic and adventurous, very fun but also emotional and has some resonance,” Waititi told the Sydney Morning Herald. “Wanting these characters who are larger than life to experience real human emotions and being part of the human condition."
It's the return of Hemworth and Waititi's dynamic duo, after the pair teamed up for the third Thor film Ragnorak and were credited with breathing new life into the franchise.
The film also stars Tessa Thompson as Valkyrie, Christian Bale as villain Gorr the God Butcher, Russell Crowe as Zeus, and cameos from Marvel stalwarts like Chris Pratt. Additionally, there's a few cameos that — no spoilers — earned a joyous reaction from the audience.
“That’s the genius of Taika,” Hemsworth continued. “In all of his films, there’s a great comedic element, there’s a great sense of fun and adventure, but underneath it you’re being taught something. There’s something beautiful and personal and relatable to everybody.”
Thor: Love and Thunder is out in Australia on July 7.