Robert Collier (26 January 1845 - 22 December 1909), known as the 2nd Baron Monkswell, of Monkswell in the County of Devon from 1886, was a barrister and Liberal Party politician. He was the eldest son of Robert Porrett Collier (1817-1886) and Isabella née Rose. His father was a Liberal Party member of parliament for Plymouth until 1871 when he became a judge. A year before his death he was created the 1st Baron Monkswell, the title being derived from his Devon property.