In 1958 Thomastown Vocational school was built by Co. Kilkenny Vocational Education Committee on a site purchased from Mr O’Carroll. The school’s first principal was Mr Walter Cleary.

This was an important development for the area because it was the only 2nd level school except for the secondary top established by the Mercy Sisters in 1950 which provided education for girls only.

The original school was small by today’s standards. It consisted of 3 classrooms – kitchen, general class room and woodwork room with store attached. Beside the school a very ornate bicycle shed was built. The original buildings still stand and are currently in use as classrooms but the bicycle shed has found another use. At first the students (boys and girls) were prepared for the Day Vocational Certificate (Group Cert) and achieved excellent results. The range of subjects was limited to General subjects, Woodwork, Domestic Science and Typing. Following Group Cert, students left to take up employment, go into trades and farming.

Adult education classes at night were a very important element of education for people whose full time education finished at primary school. Many practical skills were thought at night.

In 1967, with the advent of free education the Technical School and the Secondary Top amalgamated. Two Sisters of Mercy (Sr. Carmel and Sr. de Sales) joined the staff bringing with them 1st, 2nd and 3rd year students. Sr. Carmel remained on the staff until 1986. The link with the Mercy Sisters ceased at this stage as she was not replaced by a Mercy Sister. This amalgamation, together with the introduction of free education, caused an explosion in the number of students. While it was welcomed, it posed accommodation problems. The promised new “state of the art” school was delayed until 1985. Meanwhile it was common practice to have 2 classes in each room even in the relatively small pre–fabs. Other classes were held in the entrance hall, the woodwork store, the bicycle shed, while others had to walk to the CYMS hall and to the Concert Hall where they would remain for 2 or 4 class periods at a time.

At that time teachers had to be very versatile as many new teachers moved to “Greener Pastures” as soon as career opportunities arose elsewhere. These were difficult days but staff and students accepted the conditions and the school flourished.

Despite these difficulties, new subjects were added to the curriculum and students sat 2 exams, Group Cert in 2nd year and Intermediate Certificate in 3rd year. This continued until the 2 exams were amalgamated into the Junior Certificate in 1993.

Under Mr Luke Murtagh who replaced Walter Cleary as Principal the school was given permission to do the Leaving Certificate programme. The first group of students sat the L. C. in 1975. This included many who had to transfer from Ballyhale because Ballyhale did not have L. C. at that stage. This was a huge step forward for the students, the school and the population of the surrounding area because now the students of Thomastown could compete with students in secondary schools for places in 3rd level education and for occupations demanding L. C. Bishop Forristal, a native of Thomastown, has said that prior to this only those students in Thomastown who could afford to go to boarding school were able to do the L. C. Since then many of the students have gone on to 3rd level Education where they have been very successful studying to the highest level and can now be found in all walks of life.

The school has always been to the forefront in developing new courses and meeting new challenges. Under Mr Murtagh it was one of the first schools to develop a Transition year programme in 1967 in conjunction with the Dept. of Education. This was then called a Work Experience class because of the introduction of Work Experience into the curriculum which was unheard of at that time.

The school was a pioneer also in the area of Equestrian studies and was one of the first schools to provide equestrian education when the course commenced in 1978. Since then other schools have modelled their courses on the Thomastown experience. Another development, under Mr Patrick Cronin as Principal was the establishment of Grennan Mill Craft School to provide education in the Arts in 1981. The establishment of these courses is a tribute to Co. Kilkenny VEC and the school principals and staff who saw the need for courses in Equestrian studies and Craft which are indigenous to Kilkenny. The Secretarial course which is one of the original areas of education in Technical schools continued in the school but it has developed, changed and adapted over the years to meet the changing world of work and changes brought about by new technology.

Under Mr Timothy O Mahony the school developed a gardening course – a joint venture between the college and Kilkenny Co Council. The practical work of the course is undertaken in Woodstock Gardens, Inistioge which are being restored. These PLC courses are to this day very important areas of education.

The Equestrian course and the Craft course brought students from all over Ireland and even from abroad to Thomastown which was a boost to the local economy because these students went into accommodation in the town.

After many years the Dept. of Education sanctioned the building of the “state of the art” new school. This was built on the site of the original school and incorporated it. It consists of 2 science labs, a home economics room, an engineering room, a woodwork room, an art room, 8 general purposes rooms, a computer room, offices and a canteen. The provision of a canteen meant that students could avail of hot meals at lunch time. This school was officially opened by Ms Gemma Hussey, Minister for Education in 1986.

Unfortunately this new school has proved too small already and pre-fabs are still in use where there is a sacred space, a library, a learning support room.

The school underwent a major refurbishment programme in 2005 which means that the facilities now are the most updated and modernised. These refurbished rooms were officially opened by Ms Mary Hanafin Minister for Education and Science in May 2005.

The school has an excellent relationship with, and cooperation between, the local GAA and soccer clubs and students regularly train and play on the grounds of these sporting bodies. Students take part in a wide range of sports and extra curricular activities. In the sporting field there have been many successes, some at national level, in Camogie, Basketball, Ladies Football, Hurling, Gaelic Football, Soccer, Athletics and Badminton. Famous sportspeople who are past – pupils are Dick O’Hara and Michael Reddy. Music, drama and debating are just some of the extra curricular activities of the school. While the school continues to meet new challenges, develop new curricula and new programmes these extra curricular activities are not neglected and contribute to the life of the school.

The school changed its name to Grennan College in 1996.

It’s a school which hasn’t stood still, it has always adapted and changed to meet the needs of the students of the changing world of work and, with its principal Mr William Norton and staff, faces the 21st century with the optimism and the enthusiasm to meet any new challenges.