The unlikely duo is joining forces to take on metal illness and PTSD.
Lady Gaga had a FaceTime call with royalty as she and Prince William talked mental health in a video released Tuesday.
The pop superstar joined the Duke of Cambridge's Heads Together, a campaign he leads along with his wife, to raise awareness about mental illness.
Read: Lady Gaga and Bradley Cooper Give First Glimpse of 'A Star Is Born' Remake
"It's time that everyone speaks up and really feels very normal about mental health," the prince said. "It's the same as physical health. Everybody has mental health and we shouldn't be ashamed of it and just having a conversation with a friend or family member can really make such a difference."
In December, Gaga opened up in a letter about her own battles with PTSD after she was sexually assaulted at 19 years old.
"There's a lot of shame attached to mental illness; you feel like something is wrong with you," Lady Gaga said from her Los Angeles kitchen. "I should be so happy, but you can't help it when in the morning you wake up, you are so tired, you are so sad, you are so full of anxiety and the shakes that you can barely think.”
The FaceTime comes a day after Prince Harry revealed he recently sought counseling to deal with the grief of losing his mother, Princess Diana.
“It was the best thing that could come out of my mental illness... was to share it,” Prince Harry said.
Heads Together most recently launched a series of films centered around the importance of speaking up about mental health.
Read: 91-Year-Old D-Day Veteran Scolds Prince Harry: 'You Should Have Worn a Bloody Tie'
"It's okay to have this conversation. It's really important to have this conversation," said Prince William. "You won't be judged. It's so important to break open that fear and that taboo which is only going to lead to more problems down the line."
Prince Harry plans to meet Lady Gaga when she visits the U.K. in October.
Watch: Prince Harry Reveals Mental Health Issues He Endured After Princess Diana Died
