Michael, 63, was named Best Actor in a Motion Picture Comedy or Musical for his acclaimed performance in Birdman. He used the opportunity to publicly praise his 31-year-old son Sean, who was proudly watching in the audience.
Michael Keaton accepting his award at the Golden Globes
"My best friend is kind, intelligent, funny, talented, considerate, thoughtful... Did I say kind?" Michael said, pausing as he tried to hold back the tears. "He also happens to be my son Sean. I love you with all my heart, buddy."
The Beetlejuice star had begun his speech by profusely thanking Birdman director Alejandro González Iñárritu. He then began to talk about his upbringing as the youngest of seven children in a household where "the themes were pretty simple".
"Work hard, don't quit, be appreciative, be thankful, be grateful, be respectful," he explained. "Also don't whine ever. Don't complain and always, for crying out loud, keep a sense of humour."
Michael Keaton's emotional address has since gone viral
Michael also spoke about his parents, his "six wonderful brothers and sisters", and his "tremendously tremendous and loving friends all over the world", before addressing his only child Sean.
The star concluded his speech by telling the audience with a smile, "Shoot, two things I said I wasn't going to do: cry and give air quotes! Damn. I'm so grateful, honestly, from the bottom of my heart.
"You have no idea what this means to me," he added. "To come from the place where I come from, I'm proud of all my friends and family. Thank you very much."