James Michael Leathes Prior, Baron Prior, was a British Conservative Party politician. A Member of Parliament from 1959 to 1987, he represented the Suffolk constituency of Lowestoft until 1983 and then the renamed constituency of Waveney from 1983 to 1987, when he stood down from the House of Commons and was made a life peer. He served in two Conservative cabinets, and outside parliament was Chairman of the Arab British Chamber of Commerce from 1996 to 2004.

Lowestoft was a parliamentary constituency centred on the town of Lowestoft in Suffolk. It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected by the first past the post voting system.