Roberta Flack Selected for Walk of Fame in 1999, Never Set Date for Unveiling

Roberta Flack's body of work was so legendary she was selected for a star on the Walk of Fame back in '99 -- but good luck finding it on the iconic street!

Ana Martinez from the Hollywood Walk of Fame tells TMZ Roberta never locked in a date for the ceremony -- but now, she's hoping Roberta's family will reach out to the Hollywood Chamber of Commerce to finally set up a posthumous honor.

Ana tells us the Hollywood Chamber of Commerce hopes Roberta's family will reach out -- but if they do, it'll have to wait until after 2025 since all the dates for this year are fully booked.

We're told the same thing happened with Whitney Houston -- she got the green light for her star, but never locked in a date for the big unveiling.

Roberta was 88 at the time of her death ... capping off an incredible career that took off in the '70s with hits like "The First Time Ever I Saw Your Face" and "Killing Me Softly."