His father was a Czech refugee who came to Britain in 1938. Lampl was born in Wakefield and as the family later moved he was educated at Reigate Grammar School and Cheltenham Grammar School. He has said that the contrast between the Oxbridge entrance rates from these two schools alerted him to the differences in educational opportunity in Britain. He studied at Corpus Christi College, Oxford and the London Business School.
In 1983 he created The Sutton Company, a private equity firm, and by the mid 1990s had become extremely wealthy. Since then he has founded the Sutton Trust and engaged in various campaigning and philanthropical projects, notably the "Open Access" scheme which widened access to the academically selective The Belvedere School in Liverpool.