Sir John "Jack" Stewart-Clark, 3rd Baronet (born 17 September 1929) is a British businessman and former Member of the European Parliament (MEP).

He also attended Balliol College, Oxford, followed by the Harvard Business School,[2] after his National Service, during which he had been commissioned into the Coldstream Guards in 1948, serving in North Africa.

Stewart-Clark stood in the General Election of 1959 as Unionist candidate for Aberdeen North, coming second to Hector Hughes.

In the first direct elections to the European Parliament, in 1979, Stewart-Clark successfully stood in Sussex East, holding the seat until it was abolished in 1994.

The castle, built in 1818 adjacent to a 15th-century tower house, had been bought by Stewart-Clark's great-grandfather, the Paisley thread manufacturer Stewart Clark, in 1899.

[7] In 2016, Stewart-Clark gained approval from the Vatican to take a Passion Play, dramatising the last days of Christ, to the Opera Jail in Milan, Italy.