Abel Decaux (11 February 1869 – 19 March 1943) was a French organist and composer. He studied organ with Charles-Marie Widor and Alexandre Guilmant, and composition with Jules Massenet. He served as organist at the Basilique du Sacré-Cœur, in Paris, for 25 years until 1923, when he went to the USA to teach organ at the Eastman School of Music in Rochester, NY. He returned to France in 1935, to teach organ at the École César Franck and at the Institut Grégorien in Paris.