Giants co-owner John Mara announces cancer diagnosis, will remain active with team during treatment
New York Giants co-owner John Mara was diagnosed with cancer, he announced Monday. Mara, 70, said he plans to remain active with the team as he undergoes treatment.
Mara announced his diagnosis in a statement posted by the Giants on X. Mara did not provide specific details on his diagnosis, but said he is "feeling strong and optimistic" as he readies for treatment.
- New York Giants (@Giants) September 29, 2025
Mara is the grandson of Tim Mara, who was the founding owner of the Giants in 1925. Upon Tim's death in 1959, the team was left to his son's Jack and Wellington Mara. Wellington is John's father.
John first started working for the Giants in 1991 as the team's general counsel. He worked his way into larger roles, eventually taking over as co-owner when Wellington died in 2005.
During John's first season as co-owner, the Giants won the NFC East but lost in the wild-card round. The team was again eliminated in the wild-card round the following season before going to the Super Bowl in the 2007 season, where they upset the 18-0 New England Patriots.
The Giants won a second Super Bowl under Mara in the 2011 season, when they again upset the Patriots in a rematch.