Jeffrey Adler is a Canadian CrossFit athlete.

In 2023, he won the title of "Fittest on Earth" at the 2023 CrossFit Games.

[11] In 2024, Adler withdrew from the 2024 CrossFit Games following Lazar Dukic's death during Event 1.

[12] In the same year, Adler won the 2024 Rogue Invitational for the first time.

[13] Adler is engaged to his training partner and coach Caroline Lambray,[5] with whom he co-founded an affiliated CrossFit gym, CrossFit Wonderland, in Montreal.