Ralph de Lumley, 1st Baron Lumley

Ralph de Lumley, 1st Baron Lumley (c. 1360 – January 1400) was an English peer.

Lumley was the second son of Sir Marmaduke de Lumley and his second wife, Margaret de Holand. He married Eleanor de Neville (died after 1441), the third daughter of John Neville, 3rd Baron Neville de Raby. Their children included:

• Thomas de Lumley (died 1400)
• John Lumley (1383–1421)
• Marmaduke Lumley (died 1450)
• Catherine de Lumley (1396–1461), married Sir John Chidioc. They were parents of Margaret Arundel who married Baron John la Zouche.

In 1384, Richard II created Lumley Baron Lumley by writ of summons. He was captured by the Scots at the Battle of Otterburn in 1388 but released by 1389. He was granted permission to build and crenellate a castle at Lumley in 1392. He joined the conspiracy to murder Henry IV and restore Richard II in 1399 (known mainly as the Epiphany Rising), but was captured and beheaded (at Cirencester), attainted in Parliament in March 1401 and his peerage forfeited to The Crown. His grandson, Thomas obtained a reversal of the attainder in 1461.