Sir Ronald Charles Lindsay GCB GCMG CVO PC (3 May 1877 – 21 August 1945) was a British diplomat.

[12][13][14] He was the first ambassador to move into the brand-new British embassy in 1930,[15] and remained in Washington for almost a decade, retiring in June 1939 to be replaced by Lord Lothian.

[6] Lindsay served an extraordinarily long term of nine years as U.S. ambassador, also as the Dean of the Diplomatic Corps from July 1934 to August 1939,[16] his tenure being extended because of his effectiveness as a diplomat and the growing importance of American assistance during the years leading up to World War II.

[17] His last major official act as ambassador was to host the 1939 Royal Garden Party for King George VI and Queen Elizabeth during the first-ever visit to the United States by a reigning British monarch.

[18][19] The Royal Garden Party at the British embassy was considered the social event of the year in Washington.