John David Gwynn (13 July 1907 – 21 November 1998) was a civil engineer with a special interest in renewable energy generation. In his youth he was one of Ireland's most distinguished cricketers. John David Gwynn (known to family and friends as "David" or "JD") was born in Dublin on 13 July 1907. He was the eldest child of Edward Gwynn, an academic and sometime Provost of Trinity College Dublin, and Olive Mary Gwynn née Ponsonby. In accordance with family tradition he was educated at St Columba's College, Dublin and then at Trinity College Dublin, where he studied civil engineering. While still an undergraduate he was employed by the Siemens company to assist in their work on the Shannon hydroelectric scheme.