Ernest William Beckett, 2nd Baron Grimthorpe (25 November 1856 – 29 April 1917), born Ernest William Beckett-Denison, was a British banker and Conservative politician who sat in the House of Commons from 1885 until 1905 when he inherited the Grimthorpe peerage.
Beckett was the eldest son of William Beckett, younger son of Sir Edmund Beckett, 4th Baronet and Hon. Helen Duncombe, daughter of William Duncombe, 2nd Baron Feversham. Beckett was the nephew of Edmund Beckett, 1st Baron Grimthorpe and great nephew of Sir John Beckett, 2nd Baronet.
Beckett was educated at Eton College and Trinity College, Cambridge, though he failed to complete his first year at university and dropped out to travel abroad. He later became a partner in the banking firm of Beckett & Co, of Leeds, owned by his father.
He was a major in the Yorkshire Hussars Yeomanry Cavalry, was commissioned as an Assistant Adjutant general in the Imperial Yeomanry on 28 February 1900, during the Second Boer War, and returned to the Yorkshire Hussars when he resigned from active duty in July 1902.
In 1885, Beckett was elected Member of Parliament for Whitby, a seat he held until 1905, though he is rarely mentioned in Hansard. In 1886, he resumed the name Beckett in place of Denison. In 1905 he succeeded his uncle Lord Grimthorpe as 2nd Baron according to a special remainder in the letters patent, as well as in the family baronetcy. However, he squandered much of his inherited family wealth and in 1905 he was also sacked as a senior partner in the family bank by his two brothers because of his expensive tastes and personal debts. He had once commissioned a bronze bust of his then fiancée Eve Fairfax from the famous sculptor Auguste Rodin which he subsequently could not pay for. He was forced to sell his houses in London and Virginia Water. He was even forced to sell his family home Kirkstall Grange to Leeds City Council to repay massive debts, and it is now part of Leeds Beckett University.