Secret Story is a French reality competition television show. Despite not being a direct adaptation of the Big Brother franchise's format, created by producer John de Mol Jr. in 1997, the show has a similar concept while including its own game mechanics, and is also produced and owned by Big Brother's production company Endemol Shine Group/Banijay.

It follows a group of contestants who live together in a specially constructed house named La maison des secrets (The House of Secrets) that is isolated from the outside world for a cash prize. The contestants are continuously monitored during their stay in the house by live television cameras as well as personal audio microphones. Throughout the course of the competition, contestants are evicted from the house, by being voted out of the competition by the spectators. All contestants have a secret that they try to hide, while trying to discover the other housemates' one. Finding a secret allows the candidates to add money to their prize pool, while the candidate whose secret was discovered loses money. Several challenges and secret missions are also offered to the candidates during the adventure to help them earn money or clues.

The show was hosted by Benjamin Castaldi for the first eight seasons, and by Christophe Beaugrand from the ninth to twelfth seasons.

Each seasons are composed of daily shows that airs during the afternoon, except on Sundays. From the first to the eleventh seasons, the show also featured weekly live shows that aired on Friday evening to reveal the evicted member of the week. For the twelfth season, only the inaugural and final shows aired in the evening, with the eviction live shows replaced by a live daily show on Friday afternoon. From the third season onwards, the live shows were followed by an after show titled After Secret, co-hosted by Castaldi and Adrien Lemaître from seasons three to eight, and Beaugrand from the ninth to twelfth.

Secret Story premiered on 23 June 2007 on TF1. For the ninth season, the daily and after shows moved to NT1 while the live shows where still airing on TF1. Following a ratings declined, the tenth and eleventh seasons where moved completely to NT1, with TF1 only airing the first live show of each seasons. In May 2018, the show was canceled after eleven seasons. In October 2023, the TF1 Group announced that the show will be revived in 2024. The revival premiered on 23 April 2024 on TF1, with the after shows on TFX. In November 2024, it was again cancelled by TF1 following a conflict between the network and Endemol France regarding the budget for a potential thirteenth season.

Secret Story has spanned a franchise with numerous international adaptations including Portuguese, Dutch, Peruvian, Lithuanian, Spanish, and French-African versions. Some of his game mechanics were also used in selected seasons of the Big Brother franchise internationally.