James Williamson, 1st Baron Ashton DL (31 December 1842 – 27 May 1930) was a British businessman and Liberal Party politician, whose family business in Lancaster produced oilcloth and linoleum which was exported around the world.
He was born the third of four surviving children to James Williamson Snr, who had established a successful coated fabrics business in the town in the 1840s. James jnr was educated at Lancaster Royal Grammar School and worked all his life in the family business.
With his father he created the city's Williamson Park, on the site of former stone quarries on Lancaster moor. After the death of his second wife, Jessie, who supported him in his political life, he built the Ashton Memorial on a hill in the park; the Edwardian baroque building is now used for exhibitions and for weddings. He also donated the city's Town Hall and a monument to Queen Victoria in the city's Dalton Square.
He bought Ashton Hall in 1884, serving as High Sheriff of Lancashire for 1885. In the 1886 general election, Williamson was elected to the House of Commons as Member of Parliament (MP) for Lancaster, and held his seat at the 1892 election. In 1895 he was elevated to the peerage as Baron Ashton, of Ashton in the County Palatine of Lancaster and in 1920 made Constable of Lancaster Castle for life. He was a Deputy Lieutenant of Lancashire.