| Honorific-Prefix: | The Right Honourable |
| The Lord Winster | |
| Order1: | Minister of Civil Aviation |
| Term Start1: | 4 August 1945 |
| Term End1: | 4 October 1946 |
| Monarch1: | George VI |
| Primeminister1: | Clement Attlee |
| Predecessor1: | The Viscount Swinton |
| Successor1: | The Lord Nathan |
| Order2: | Governor of Cyprus |
| Term Start2: | 24 October 1946 |
| Term End2: | 4 August 1949 |
| Monarch2: | George VI |
| Predecessor2: | Charles Campbell Woolley |
| Successor2: | Sir Andrew Barkworth Wright |
| Birth Date: | 27 March 1885 |
| Death Date: | 7 June 1961 |
| Death Place: | Uckfield, Sussex |
| Nationality: | British |
| Party: | Labour |
Reginald Thomas Herbert Fletcher, 1st Baron Winster, (27 March 1885 – 7 June 1961) was a British Liberal then Labour politician. He was Minister of Civil Aviation under Clement Attlee between 1945 and 1946 and Governor of Cyprus between 1946 and 1949.
Following service during the First World War as a Royal Navy officer Fletcher was elected as Liberal Member of Parliament (MP) for Basingstoke in 1923 by 348 votes but lost the seat in 1924. In 1935 he was elected as Labour MP for Nuneaton. He was raised to the peerage as Baron Winster, of Witherslack in the County of Westmorland, in 1942 and made a Privy Counsellor in 1945. From 1945 to 1946 he was Minister of Civil Aviation in the government of Clement Attlee. The latter year he was appointed Governor of Cyprus, a position he held until 1949.
Lord Winster died in 1961 at the age of 76 in the Uckfield Rural District, Sussex. The peerage became extinct on his death.