Big Brother 2025 (U.S. Season 27) started on Thursday, July 10, 2025 , with a 90‑minute premiere on CBS from 8:00–9:30 p.m. ET.

Quick Scoop: Big Brother 2025 Start Date

For anyone searching “when did Big Brother start 2025,” here’s the key info in one place.

  • Premiere date: July 10, 2025
  • Night: Thursday
  • Premiere length: 90 minutes (8:00–9:30 p.m. ET)
  • Network: CBS in the U.S.
  • Season: Big Brother 27 (the 2025 summer season)

Schedule Basics

After the premiere, the show settled into its usual multi‑night weekly rhythm.

  • Regular episodes aired Sunday, Wednesday, and Thursday.
  • Sunday and Thursday episodes: about 1 hour.
  • Wednesday episodes: extended to 90 minutes, a first for the franchise.

Extra 2025 Twists

The 2025 season added some expanded content and tweaks that helped it trend through summer 2025.

  • A shorter overall season compared with some recent years, wrapping in late September 2025.
  • Additional companion content on select Fridays featuring former houseguests, exclusive clips, and analysis segments.

Fans on forums and social platforms often tag this as the “hotel mystery” season because of the themed house design and promo branding in 2025.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.