After 15 years away from the limelight, TLC should be coming back to regain its crown. But in reality, it never lost it.

A quarter of a century after the trio released its first album “Ooooooohhh . . . On the TLC Tip,” the Atlanta outfit remains America’s biggest-selling girl group of all time (and is second only to the Spice Girls worldwide).

The ’90s saw TLC dominate the music industry, with more than 65 million album sales, four Grammys, and Billboard No. 1 singles such as “Waterfalls,” “No Scrubs” and “Unpretty” to its credit. But internal conflicts and the sudden death of member Lisa “Left Eye” Lopes in a car accident in 2002 derailed the group’s fortunes.

Now, remaining members Tionne “T-Boz” Watkins and Rozonda “Chilli” Thomas are back with “TLC” — their first album in 15 years, which was paid for by fans who pledged over $430,000 to the group via Kickstarter. They’ll also be part of the nationwide “I Love the 90’s” tour this summer, performing alongside acts such as Naughty by Nature and Montell Jordan.

“There’s never been talk of replacing Lisa — that was always other people talking,” Thomas, 46, tells The Post. “We made a pact in this group that nobody can be replaced — it was meant for the three of us, and now just for the two of us. This is our new normal.”

Do you think that the common, body-positive messages in today’s pop music are partly due to TLC’s work?

You never know whose lives you’re affecting. I remember one fan said she was thinking about getting breast implants because her boyfriend wanted her to, but then she saw the “Unpretty” video [released in 1999, in which a character agonizes over the same decision] and it spoke to her. She told me that’s what persuaded her not to do it. I told her to only do it if it’s something you want to do for yourself. If someone won’t accept you for who you are, then dump them! It’s that simple!

Katy Perry donated $5,000 to your album campaign. Has she discussed the importance of TLC in her own life with you?

We haven’t been able to talk because we’ve both been working. She has a slumber party waiting for her [as part of a reward for her contribution]. All of us have to be wearing onesies, and we want to watch scary movies. Not paranormal-type stuff, but a good action film or a thriller.

So not “The Exorcist”?

Oh, [clearly terrified] no, no, no. I don’t like to watch those scary, based-on-true-stories kind of films. It’s actually because of that movie that I still cannot sleep in the dark. I don’t know why, but my mom took me to see it when I was a kid — still in my single digits — and I have been messed up ever since!