Catherine O'Hara may be gone ... but she lives on, thanks to her famous friend Martin Short.

On Friday, Netflix dropped the trailer for their upcoming doc about the "Only Murders in the Building" star ... which includes some shots of the late legend.

The teaser is full of Martin's A-list acquaintances singing his praises ... and even shows him singing Catherine's, too.

A quick clip shows the funnyman gushing over her, saying ... "I loved you in 'Home Alone!'"

Another shows Catherine raving about Martin's comedy chops and his ability to "improvise to eternity."

These two go way back ... they met in their younger years. In January, Martin made a touching tribute to his late friend during a comedy show with Steve Martin.

He said ... "Catherine O’Hara, I met when she was 18 years of age, and all these years later, she has been the greatest, most brilliant, kindest, sweetest angel that any of us worked with."

Watch Catherine's posthumous appearance in the new trailer.

RIP