Alun School is a secondary school located in the community of Mold, Flintshire, Wales. It was formed in 1970 as a result of the merger of the Alun Grammar School and the Daniel Owen Secondary Modern School.

Some of the school's present buildings, such as the Daniel Owen Building, date from 1938. The remainder were opened on the formation of the current comprehensive or built in the years since. In 1989, 1432 students attended the school; by 2009 the number was 1762, with over 550 students in the sixth form and over 120 teachers. The main school remains over-subscribed and the Sixth Form is one of the biggest in Wales.

The school is sometimes known colloquially as Mold Alun, to distinguish it from the nearby Castell Alun secondary school in Hope.

The Alun has many distinguishable buildings and areas. These include:

The Lloyd Parry Building, Tower Block, Daniel Owen Building, Central Block are all connected.

Headteachers of Alun School / Alun County Secondary School / Alun Grammar School

Headteachers of Daniel Owen Secondary Modern School / Central School

Headteachers of Alun School (became comprehensive in 1967 and moved to present site in November 1973)