ACTRESS Lynne Marie Stewart, famous for her role in It’s Always Sunny in Philadelphia, has died aged 78.

The heartbreaking news was confirmed by her fellow Hollywood friend Cassandra Peterson.

Lynne Marie Stewart at The Groundlings 50th Anniversary event.

She wrote: “My heart is breaking upon hearing the news of my dear friend @lynnestewart78 Lynne Stewart’s passing. One of the kindest, sweetest, funniest women who ever lived.

“The iconic Miss Yvonne of Pee-wee’s Playhouse: She’ll always be ‘the most beautiful woman in Puppetland’.”

Heartbroken fans flooded the comments with tributes to the beloved actress.

Lynne Marie Stewart at a film premiere.

One fan wrote: “So sorry to hear, sending prayers for peace.”

Another person said: “I’m so sorry to hear this!

“She was my favourite on Pee Wee’s Playhouse, I wished to be that beautiful.

“And she was so good on it’s always sunny.”

Pee-wee's Playhouse,' 'It's Always Sunny' star Lynne Marie Stewart dead at 78

A third fan wrote: “Heartbreaking news. I loved Lynne.”

The American TV star was best known for playing Charlie’s mom, Bonnie Kelly, on the long-running series It’s Always Sunny in Philadelphia.

Stewart was also famous for playing Miss Yvonne, The Most Beautiful Woman in Puppetland, in several Pee-Wee Herman shows.