Stage 1 of the 2026 Itzulia Basque Country was a hilly stage that took place on .

The stage started in Iturribide / Prim and finished in Arabella, starting at with an expected finish at (average speed of 48 km/h).

The total distance of the stage was 13.8 km. The stage included 0 categorized climb(s) and 0 checkpoint(s), and had a total elevation gain of 222 m, and a total descent of 253 m.