| Club: | Bilbao Athletic |
| Season: | 2015–16 |
| Chrtitle: | President |
| Chairman: | Josu Urrutia |
| Mgrtitle: | Head coach |
| Manager: | José Ángel Ziganda |
| Stadium: | San Mamés |
| League: | Segunda División |
| League Result: | 22nd (relegated) |
| League Topscorer: | Ager Aketxe (8) |
| Season Topscorer: | Ager Aketxe (8) |
| Largest Win: | Bilbao Athletic 3–1 Mallorca Bilbao Athletic 2–0 Llagostera Bilbao Athletic 4–2 Ponferradina Bilbao Athletic 2–0 Tenerife |
| Largest Loss: | Bilbao Athletic 0–4 Gimnàstic |
| Pattern La1: | _athletic1516h |
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| Leftarm1: | F42122 |
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| Pattern B2: | _athletic1516a |
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| Prevseason: | 2014–15 |
| Nextseason: | 2016–17 |
The 2015–16 season was the 52nd season in the existence of Bilbao Athletic and the club's first season back in the second division of Spanish football since the 1995–96 campaign 20 years earlier.[1] During this season, Bilbao Athletic participated in the Segunda División, and also entered the season's edition of the invitational Premier League International Cup for age-restricted teams.
| Date | Name | Moving to | Fee |
|---|---|---|---|
 | Free[3] | ||
| | Loan return[4] | ||
| | Loan return[5] | ||
| Date | Name | Moving to | Fee |
|---|---|---|---|
| | Unattached | Free[6] | |
| | Free[7] | ||
See main article: 2015–16 Segunda División.
The league fixtures were announced on 14 July 2015.[8]