The 70-year-old actor won the award for outstanding performance by a male actor in a television movie or limited series for his performance in "Dopesick." The Hulu series is based on the book of the same name and chronicles the country's opioid crisis, an issue that is deeply personal for Keaton.
Keaton's nephew, also named Michael, died in 2016 following an accidental overdose of heroin and fentanyl, and the Oscar nominee got emotional at the end of his speech over his devastating loss.
"Given the subject matter, this is for my nephew, Michael, and my sister, Pam," Keaton said while trying to hold back tears. "I lost Michael ... and it hurts. To my sister Pam, thanks."
Earlier in Keaton's speech, he spoke about the power of a project like "Dopesick" and the awareness it can bring to issues such as addiction.
"I have a job where I can be part of a production that actually can spawn thought, conversation, actual change," said Keaton, who plays a doctor in a coal-mining town overwhelmed by OxyContin. "Who gets to have that job? Seriously? How fortunate am I that good can come from something I do just because I learn to become an actor?
"There's massive inequity in the world," he continued. "In 'Dopesick,' when you talk about addiction, the way to heal the problem is to accept that you have a problem. Not our country. The entire world. Economically, racially, socially, financially. There's massive inequity in the world. There just is. There's fair, and there's unfair. There's not a lot of room in between."
In an interview with USA Today in October 2021, Keaton admitted that it wasn't an easy decision to join the show.
"If the writing wasn't good and the quality of the people involved wasn't as high, I can't guarantee that I'd have done it," the actor said, "just based on losing Michael."
Showrunner Danny Strong revealed to Metro UK that Keaton was the only actor they had in mind for the role.
"Michael was passionate about the subject matter because his nephew had passed away from an overdose," Strong said. "So it was something he was personally connected to, as well. So yeah, we offered him the role and he accepted."