St. Farnan's, which is managed by Co. Kildare V.E.C., has served the community since September 1941. During the period 1941 to 1969 the school would have offered the Group Certificate programme to boys and girls from the area. The catchment includes Prosperous itself as well as the surrounding districts such as Allenwood, Coill Dubh, Allen, Kilmeague, Staplestown, Robertstown, Donadea, Timahoe and to a lesser extent Clane.

The rapid educational developments of the sixties saw a sudden growth in pupil numbers as well as the right of Vocational School pupils to sit the Intermediate Certificate examinations as well as the Group Certificate.

From 1969 to 1975 pupils in St. Farnan's were restricted to following these Junior Cycle programmes only. Those wishing to follow the Senior Cycle courses were expected to transfer to Naas to do so. In practice only a small number of pupils did transfer to Naas. As a result of this most pupils who had completed the Junior Cycle left the education system. The school leaving age was 15 in 1972 and the majority of St Farnan's pupils left school at or shortly after reaching the statutory age for compulsory education. After much agitation and protest the school was granted Senior Cycle status in 1975 and St. Farnan's pupils first sat the Leaving Certificate Examinations in their own school in 1976.

In more recent times the school has attempted to remain abreast of educational developments by providing Junior Certificate, Junior Certificate Schools Programme (JCSP), Leaving Certificate, Leaving Certificate Applied (LCA) and Post Leaving Certificate (PLC) courses. The school has also provided Transition Year and Leaving Certificate Vocational programmes when suitable to the pupil cohort.

The original school building opened in 1941. The flat roofed extension was opened in 1971. The next phase was completed in 1989 and officially opened by Minister Mary O'Rourke T.D. in September 1991. The new extension was completed in 2007 and Minister Mary Hanifin officially opened this in October of that year.

School facilities now include a purpose built Art room with Kiln, two Science Labs, a Demonstration room, two high tech ICT rooms, a Music room, a CAD Lab, Engineering, Construction & Home Economics rooms, full size Gym with Fitness Suite and Canteen area. The school is built for 450 students which leaves us equipped to cater for the future growing numbers in our catchment area.

Our Patron - Saint Farnan of Downings

According to Father O'Hanlon (Lives I.S.S. 2, p. 564.) the site of the old Church at Downings was once the cell of St. Farnan, whose feast occurs in the Irish Calendar on the 15th of February. This saint flourished in the sixth century, and was descended from King Niall of the Nine Hostages.

Beside the ancient cemetery is the Well of St. Farnan; and it possesses-so the local story goes-the valuable property, that those who drank of it never afterwards have any relish for intoxicating drinks. Activated by the popular belief, St. Farnan blessed the well at Downings and called it the "Well of Sobriety", saying that "whosoever drank of its water should never again relish the waters of intemperance". No other details or traditions survive regarding St. Farnan.