Brecknock Wildlife Trust (Welsh: Ymddiriedolaeth Natur Sir Frycheiniog) is a former wildlife trust covering the vice county of Brecknockshire in Wales. The Trust was founded in 1964, with a network of volunteers carrying out most of its work. No full-time conservation officers were in post until 1987. Heritage Lottery funding helped the Trust to expand and a bequest of £1,000,000 in 2003 resulted in the appointment of a Reserves Officer. In April 2018 it merged with The Wildlife Trust of South and West Wales.