Robert Singleton (died 1544), also known as John, was an English Roman Catholic priest, executed on a treason charge.
He is considered a Catholic martyr by Antonio Possevino, in his Apparatus Sacer.
He belonged to a Lancashire family and was educated at the University of Oxford, but does not appear to have graduated.
He became a priest, and for some utterances which were accounted treasonable was brought before a court of bishops in 1543.
He was executed at Tyburn on 7 March 1544, along with Germain Gardiner and John Larke.