The first ever carnival was held in the summer of 1904 and over its history has seen many changes. Before 1940, Carnival Day and May Fair Day were two of the big days in the Rhayader calendar.

From the early 1920’s to 1939 the carnivals were organised by Rhayader Chamber of Trade. They were held in August and on a Thursday, which was half day closing. During the afternoon there were various entertainments and confetti battles, later there would be the judging of the classes and the parade, finishing with a dance in either the St Clements Hall (now the Leisure Centre) or the Drill Hall (where  the Mace supermarket was). Through the 1930’s music for the dance was usually provided by "Ray’s Rhayader Rhythmics".

Entries for the classes would come from the whole surrounding area, likewise the locals would also go to the neighbouring carnivals; they didn’t go to the effort of making the costumes just for the one day. Many entries were entertainment in themselves, and would keep the crowd amused for much of the day. Hundreds came into town for Carnival Day, and special train timetables were advertised for the event.

When the Carnivals re-started after World War Two, they were organised by the Parish Council through the Waun Capel Park management committee, who administered the park for the Waun Capel Park Trust. The Carnival was one of the events arranged to raise money for the upkeep of the park. The other events were sports, barbeque and children’s parties.

Voluntary help (as always) was required, and in this the Womens Institute were a great help in seeing to the preparation of the Queen and her Attendants.

Things changed with re-organisation of local government. Since then, organisation has been by a community committee appointed each year at the Annual General Meeting. From a one day event held on a Saturday, since 1984 it has been extended to include a whole week’s events, concluding with carnival day.  In 2004, it celebrated its Centenary Year, and to date Rhayader Carnival is the only one to have been held every year since restarting.