John Henry Bethell, 1st Baron Bethell (September 23, 1861 – May 27, 1945), known as Sir John Bethell, 1st Baronet, from 1911 to 1922, was a British banker and Liberal politician.
Bethell was the son of George Bethell and his wife Frances (née Tipper), and was educated at King's College London. He was a Director of Barclays Bank and of the Royal Exchange Assurance Corporation and also served twice as Mayor of East Ham and twice of West Ham. In 1906 Bethell was elected to the House of Commons for Romford, a seat he held until 1918, and then represented East Ham North between 1918 and 1922. He was created a Baronet, of Romford in the County of Essex, in 1911 and in 1922 he was raised to the peerage as Baron Bethell, of Romford in the County of Essex.
Lord Bethell married Florence, daughter of James Woolley Wyles, in 1895. They had three sons and three daughters. His eldest son Lieutenant Frank Henry Bethell was killed in the First World War in September 1915, aged 19. Lord Bethell died in May 1945, aged 83, and was succeeded in his titles by his second son John. Lady Bethell died in 1957.