Kenny Mayne Leaving ESPN After 27 Years, 'Salary Cap Casualty'

It's the end of an era ... Kenny Mayne announced he's leaving ESPN after an epic 27-year run.

"I am leaving ESPN," Mayne tweeted Monday ... "Salary cap casualty."

61-year-old Mayne -- who started at ESPN in 1994 -- thanked former ESPN execs Vince Doria and Al Jaffe for helping him get hired back in the day ... and also praised the current staff.

"I will miss the people. I will miss the vending machine set up over by the old [Scott Van Pelt] joint. We had everything. IntoTheGreatWideOpen#."

Kenny is one of the most popular ESPN personalities ever -- both as an anchor of SportsCenter and as a feature reporter.

In fact, he was so popular, Mayne was tapped for "Dancing with the Stars" back in 2006 ... but was the first to be eliminated. But, the audience loved him and he would occasionally come back to the show for hilarious cameos.

Before ESPN, Mayne was a pretty solid QB back at Wenatchee Valley Community College in Washington and later played at UNLV.

Mayne signed a free-agent deal with the Seattle Seahawks in 1982, according to ESPN ... but eventually decided on a career in broadcasting.