The commercial was broadcasted across more than 300 U.K. radio stations on Monday and featured William and the celebrities discussing the importance of listening to those in need.
"Being able to talk about how you're feeling is essential for keeping mentally fit and healthy," William said in the commercial, which was released by mental health organization Heads Together as part of their Mental Health Minute series.
"So maybe now is the time for us to stop and to really listen," William continued. "Each and every one of us has the power to make a difference to someone.
Heads Together recently launched their new project, titled Shout, a 24/7 crisis text line that can be used by the public to discuss their mental health issues with a team of trained volunteers.