Nenagh College opened as Nenagh Vocational school in 1935 to provide an education service for students in the town of Nenagh and surrounding parishes. Subjects on offer at that time were domestic economy, woodwork and metalwork. Paul Dempsey took on the role of acting principal and was assisted by Michael Lee, who was later to take up the role of School Principal.
1958 saw the re-decoration and equipping of the school building. In November, electric irons were provided for the domestic science room while more chairs were brought into the general class rooms. Student enrolment had increased to 120 in the school year 1961/62. The school now had three practical rooms and two general purpose classrooms.
The VEC Committee negotiated a 4.83-acre site at Dromin for £800 per acre with the intention of building the new vocational school. This purchase was approved in July, 1964 and a vote was taken with regard to gender of students to be enrolled; resulting in the new school enrolling both male and female students.
The school was relocated to Dromin Rd. site in 1970
In December, 1970, Nenagh Vocational School was officially opened and blessed. The building with a capacity for 250 day pupils and 320 evening students comprised of seventeen rooms, a lecture hall, a gymnasium, a woodwork room, a metalwork room, staff room and a canteen and a motor car engineering room for apprentices, coming in at a total cost of £250,000. The school was now in a position to enrol students for the Leaving Certificate. At this time the school also ran a special class for mature students which afforded them the opportunity to study for the Leaving Certificate at night.
1978 saw the day enrolment reach 357. First Extension to the School was carried out in 1984.
The new building refurbishment and extension was completed in 2013 resulting in a state of the art facility. Nenagh College recently celebrated 80 years.