Guess Who

 is a recurring challenge that originated in.

Rules
During, both tribes guessed for the identity of a former Survivor contestant by asking one yes-or-no question at a time in their tribe chats on Facebook. When they think they know the answer, they will put a guess in the main cast chat, but an incorrect guess will result in a three minute penalty. The first tribe to correctly guess the contestant wins.

The rules were modified for. A leader was appointed by both tribes, and the leader chose their own former Survivor contestant. In the main group chat on Facebook, both tribes would take turns asking yes-or-no questions to each other to try and find out the contestant's identity. Whichever tribe won the best of five rounds would win immunity.

History
The challenge debuted in as a reward challenge. Corvo won, sending Alto Mira to Tribal Council.

The retooled challenge in was played for immunity. Barentsz won, sending Bassøe to Tribal Council.