The Donostia-Donostia Klasikoa — Clásica San Sebastián-San Sebastián is a one-day professional men's bicycle road race in northern Spain that has been held every summer since 1981 in San Sebastián. It is the most important one-day race in Spain, is considered a one-day race of great prestige, just behind the 'Monuments', and contributes points towards the UCI World Ranking.

Road bicycle racing is the cycle sport discipline of road cycling, held primarily on paved roads. Road racing is the most popular professional form of bicycle racing, in terms of numbers of competitors, events and spectators. The two most common competition formats are mass start events, where riders start simultaneously and race to a set finish point; and time trials, where individual riders or teams race a course alone against the clock. Stage races or "tours" take multiple days, and consist of several mass-start or time-trial stages ridden consecutively.