The 2015–16 season was the 117th in Athletic Club's history and the 85th in the top tier.

[1][2] On 17 August 2015, Athletic defeated Barcelona 5–1 on aggregate to win the Supercopa de España, the club's first silverware since 1984.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

[4] For the second time in their history (117 years), Athletic played in the United States when they shut out Club Tijuana 2–0 in a preseason contest in Boise, Idaho on 18 July 2015.

The team's first trip to the U.S. took place on 4 April 1967 in Chicago, when Athletic beat Red Star Belgrade 3–1, also in a friendly.