The recognition comes for his acclaimed performance in Joker, which has already earned him a Golden Globe and SAG Award as well as a nomination for Best Actor at the upcoming 92nd Academy Awards. He beat out fellow nominees, Leonardo DiCaprio (Once Upon a Time in Hollywood), Adam Driver (Marriage Story), Taron Egerton (Rocketman) and Jonathan Pryce (The Two Popes).
Taking the stage at the Royal Albert Hall in London, Phoenix used his acceptance speech to speak out about the lack of diversity this awards season. This year's BAFTAs nominations list featured no non-white actors, and an all-male list of nominated directors.
"I feel conflicted because so many of my fellow actors that are deserving don’t have that same privilege. I think we send a very clear message to people of color that you’re not welcome here," Phoenix said.
He continued, "I don’t think anybody wants a handout or preferential treatment. People just want to be acknowledged, appreciated and respected for their work. This is not a self-righteous condemnation. I’m part of the problem."
"We have to do the hard work to truly understand systemic racism. I think it is the obligation of the people that have created and perpetuate and benefit from a system of oppression to be the ones that dismantle it," Phoenix concluded. "That’s on us."
Prince William, who attended the BAFTAs with his wife, Kate Middleton, also addressed the lack of diversity while awarding this year's BAFTA Fellowship to Star Wars producer Kathleen Kennedy.
"We find ourselves talking again about the need to do more to address diversity in the sector. That cannot be right in this day and age. I know [BAFTA executives] Pippa [Harris] and Amanda [Berry] share that frustration. BAFTA take this issue seriously, and following this year’s nominations have launched a full review… to ensure the opportunities are available to everyone," the Duke of Cambridge said.
A mainstay during awards season, Phoenix has used his platform to speak out about important issues.
When he won the Golden Globe for Best Actor in a Drama in January, his first thanks was to the Hollywood Foreign Press Association -- not for the award itself, but "for recognizing and acknowledging the link between animal agriculture and climate change."
"Contrary to popular belief, I don't want to rock the boat," he concluded, with a few words to his fellow actors in attendance: "It's great to vote, but sometimes we have to take that responsibility on ourselves and make some changes and sacrifices in our own lives. And I hope that we can do that. We don't have to take private jets to Palm Springs for the awards."
At the Critics' Choice Awards the week after, he went a bit more conventional, thanking his mother -- "Even when self-pity led me astray, you didn't give up on me" -- although he made sure to thank the hosting body "for going plant-based and trying to offset our carbon footprint."
As expected, Phoenix also wore the same sustainably made, custom Stella McCartney tuxedo he’s donned at the Critics’ Choice Awards, Golden Globes and Screen Actors Guild Awards. The reason behind the eco-conscious actor’s decision is to “reduce waste.”
See more on Phoenix in the video below.