The Hollywood heavyweights were pictured in apparent good spirits, as they arrived for the event on Tuesday evening ahead of the premiere of their film Dead For A Dollar.
The pair star in the Western, which is written and directed by Walter Hill, alongside actress Rachel Brosnahan.
It follows a bounty hunter (Waltz) on a search to find the missing wife (Brosnahan) of a businessman.
The actress appeared beside her co stars on the red carpet, wearing a floor-length pastel dress with shaded jewelled detailing.
Dafoe wore a black shirt and black jacket, with a dark tie, while Waltz opted for a simple tuxedo.
The evening prior saw the arrival of British superstars Harry Styles and Florence Pugh, who star in Olivia Wilde’s highly anticipated film Don’t Worry Darling.
Styles lived up to his reputation for bold fashion choices, wearing a navy suit and a baby-blue shirt with long lapels, which he matched with painted nails.
The 28-year-old was greeted by hordes of screaming fans on the red carpet.
Pugh also wore an eye-catching off the shoulder Valentino gown, with a sparkling train and black floral accessories round her legs.
The pair were joined by fellow actors Nick Kroll and Chris Pine on the carpet, as well as Wilde.
Don’t Worry Darling reportedly received a five-minute standing ovation, following the screening’s conclusion on Monday night.
The film has been the subject of much recent media attention due to reports of behind-the-scenes tension and uncertainty over details surrounding Shia LeBeouf’s departure from the project.
Ahead of its premiere Wilde said she didn’t want to contribute to “the endless tabloid gossip” and “the noise”.
Stars arriving previously at the 79th Venice Film Festival have included Timothee Chalamet, Cate Blanchett and Adam Driver.