Sun Jul 06 17:20:00 UTC 2025: ## Big Brother Season 27 Premiere Date Announced, Mystery Houseguest to Shake Things Up!

**LOS ANGELES, CA** – Get ready for another summer of scheming, alliances, and backstabbing as *Big Brother* returns for its 27th season! CBS has announced the premiere date for the long-running reality show: **Thursday, July 10th, at 8:00 p.m. ET with a special 90-minute episode.**

This season promises a fresh batch of houseguests battling it out for the grand prize, but a late announcement has stirred up extra excitement. Host Julie Chen Moonves has revealed the presence of a “mystery houseguest,” teasing fans that this individual is someone “epic” and “polarizing.”

“When I was told who this person is, I had to expect the unexpected,” Chen Moonves told Entertainment Weekly. “There’s going to be a strong reaction in both directions for this mystery houseguest.”

In addition to the premiere, *Big Brother* will air regularly on **Sundays and Thursdays** for one-hour episodes. Viewers can also catch **90-minute episodes on Wednesdays, airing from 8-9:30 p.m. ET.**

For those craving even more *Big Brother* content, CBS is introducing **”Big Brother: Unlocked,” a new show premiering every other Friday, starting July 25th, from 8-9 p.m. ET.** This show will feature three *BB All-Stars* offering never-before-seen broadcast footage, exclusive interviews, surprise guest appearances and behind-the-scenes access. According to a press release, former Houseguests will share firsthand insight and expertise as they analyze gameplay, assess the competition and give their insider’s perspective.

Die-hard fans can rejoice: **Live feeds will be available starting July 14th at 12:30 a.m. ET,** allowing viewers to keep tabs on the houseguests’ every move.

Julie Chen Moonves will, of course, be returning as host. Last season saw Chelsie Baham crowned the winner, defeating Makensy Manbeck in a decisive 7-0 vote.

While this marks the 27th season of *Big Brother*, the franchise has expanded to include *Celebrity Big Brother*, which Chen Moonves anticipates will return this winter. There has also been one season of the spinoff series *Big Brother: Over the Top,* and the *Big Brother Reindeer Games* holiday special, which aired for the first time in 2023.

Prepare for the drama, the twists, and the betrayals as *Big Brother* Season 27 is about to begin!

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