Cyndi Lauper‘s giving her review of Donald Trump‘s leadership skills … saying the former prez isn’t a good boss — because he didn’t stay loyal to his employees.

The singer-songwriter joined Christiane Amanpour on her CNN show and openly discussed her time working under DJT on the hit show “Celebrity Apprentice” during its ninth season in 2010.

When asked about her time on the show, Lauper says she joined to start up the “Give A Damn” Campaign … raising money to highlight LGBTQ+ youths.

Cyndi says the whole point was to learn better leadership skills … a lesson that fell flat on her years later when Trump started to oppose the gay community openly.

Lauper remembers Trump’s show having a large number of LGBTQ+ staffers … and, she says Trump later turning on their community proves he wasn’t such a great leader.

Trump fired Lauper from the show during week 9 of the competition … Poison singer Bret Michaels ended up winning the season a few weeks later.

Lauper caught some flak for doing the show at the time because of Trump’s comments toward her pal Rosie O’Donnell controversy she later addressed on “Ellen.”

Lauper’s vented this frustration with the former president before BTW … comparing him to Hitler back in 2016 for turning on the gay community — so, this stance is pretty well-documented.