奧薩蘇納B

Osasuna B was founded in 1962 as Osasuna Promesas, being renamed in 1991. It first reached the third division in the 1982–83 season, then again in 1987, the latter spell eventually lasting more than two decades.

From 1994 until 2000 Osasuna B was not eligible for promotion, as the main side was playing in the second level.

A change in the club structure from 2016 meant that an affiliate club, CD Iruña of the Tercera División became part of the Osasuna structure. The Iruña team had to play at least one division below Osasuna B, which soon had a consequence when the latter were relegated from their 2017–18 Segunda División B group and Iruña, who had maintained their status for 15 seasons, were administratively sent down to the Primera Autonómica de Navarra.

In the 2018–19 season, Osasuna B won Group 15 of the Tercera División. After the win over Cádiz B in the promotional play-offs, the team were promoted back to Segunda División B for the 2019–20 season.

In the summer of 2020, the Osasuna affiliation with Iruña was ended (though they would remain a local partner club) and a new arrangement was made with CD Subiza to act as the B-team's feeder.