Lieutenant Colonel Amelius Richard Mark Lockwood, 1st Baron Lambourne GCVO PC JP DL (17 August 1847 – 26 December 1928) was a British soldier and politician.
Born Amelius Wood, he was the eldest son of Lieutenant-General William Mark Wood and Amelia Jane, daughter of Sir Robert Williams, 9th Baronet. He was a descendant of Richard Lockwood, Member of Parliament for Hindon, the City of London and Worcester in the early 18th century, whose father Richard Lockwood had acquired the Lambourne estate in Essex through his marriage to Susanna Cutts. He was educated at Eton. In 1876 he resumed by Royal licence the original family surname of Lockwood (his father having assumed the surname of Wood in 1828 according to the will of his maternal uncle Sir Mark Wood, 2nd Baronet).
Lockwood joined the Coldstream Guards in 1866 but retired from the Army in 1883 with the rank of lieutenant-colonel. He sat as Conservative Member of Parliament for Epping from 1892 until 1917 and was also Provincial Grand Master of the Essex Freemasons from 1902, Vice President of the RSPCA, President of the Royal Horticultural Society and Chairman of the Governors of Chigwell School from 1893 to 1922. He was appointed a Privy Counsellor and a CVO in 1905, and raised to the peerage as Baron Lambourne, of Lambourne in the County of Essex, in 1917. From 1919 until his death he served as Lord Lieutenant of Essex. In 1927 he was appointed a GCVO.