Derek Leask (born 1948) is a New Zealand diplomat. From March 2008 to February 2013, he was the High Commissioner from New Zealand to the United Kingdom, and concurrently accredited as Ambassador to Ireland and High Commissioner to Nigeria. Leask is a career diplomat, who joined the Ministry of Foreign Affairs in 1969. Before becoming Commissioner, he was Deputy Secretary at the Ministry of Foreign Affairs and Trade in Wellington. He served as Ambassador to the European Union in Brussels from 1994 to 1999, and was earlier posted to Suva, Ottawa and London, between 1985 and 1989.