| Honorific Prefix: | His Excellency |
| Lindsay Croisdale-Appleby | |
| Office: | British Ambassador to the European Union |
| Term Start: | 21 January 2021 |
| Predecessor: | Sir Tim Barrow |
| Primeminister: | Boris Johnson Liz Truss Rishi Sunak Keir Starmer |
| Office1: | British Ambassador to Colombia |
| Term Start1: | November 2012 |
| Term End1: | 2015 |
| Predecessor1: | John Dew |
| Successor1: | Peter Tibber |
| Monarch1: | Elizabeth II |
| Primeminister1: | David Cameron |
| Birth Date: | 12 May 1973 |
| Nationality: | British |
| Alma Mater: | St Hugh's College, Oxford Lancaster University (MA) |
Lindsay Redvers Mark Seymour Croisdale-Appleby (born 12 May 1973)[1] is a British diplomat and Head of the UK Mission to the European Union. Appointed in January 2021,[2] he formally presented his credentials to the President of the European Commission on 29 July 2021.[3] He was Ambassador to Colombia from 2012 to 2015.
He studied modern history at St Hugh's College, Oxford,[4] and gained an MA in international relations and international law from Lancaster University.
Croisdale-Appleby joined the Foreign and Commonwealth Office (FCO) in 1996 and served as Principal Private Secretary to the Foreign Secretary 2010–2012. He then served as Ambassador to Colombia from November 2012[5] to 2015 before taking up an appointment as Europe Director in the Foreign Office. He was promoted to Director-General, EU Exit at the Foreign Office in 2017.
He was appointed Companion of the Order of St Michael and St George (CMG) in the 2020 New Year Honours for services to British foreign policy.[6] On 21 January 2021, he was appointed to succeed Sir Tim Barrow as Head of the UK Mission to the European Union.[7]
He married Barbara Jaimes-Quero in September 2003 and they have a son and a daughter. He has an older brother.