Ronald Macmillan Algie (1888 - 1978) was a New Zealand politician who served as Speaker of the House of Representatives for six years in the 1960s. He described himself as "a Tory in the old tradition".

Algie was born on 22 October, 1888, in Wyndham, a small town in New Zealand's Southland region. He was educated in Arrowtown and Balclutha before attending Auckland University. He gained an LLB in 1913 and an LLM in 1915. In 1920, he became Auckland University's first Professor of Law, aged thirty-one. He was noted for his strong intellectual performance, and also for his conservative views.

In 1937, Algie became the director of the Freedom Association, an organization which strongly opposed the left-wing Labour Party government of the time. The Freedom Association quickly became linked to the new National Party, and Algie became one of the party's more prominent supporters. In the 1943 elections, Algie was selected as the National Party's candidate for the Remuera seat, controversially displacing sitting National MP William Endean. Algie won the seat and entered Parliament.

Algie proved to be a skilled Parliamentary debater, and has been described by Hugh Templeton as the best debater of his time. Even opponents such as Bob Semple respected Algie's rhetorical abilities. He was also noted for remaining polite throughout debates, and for his willingness to apologise for any offense he accidentally gave.

After the 1949 elections, when Sidney Holland formed the first National Party government, Algie was immediately elevated to Cabinet. He was initially appointed Minister of Education, and later became Minister of Broadcasting and Minister of Scientific and Industrial Research. He also co-led the committee that looked into the future of the Legislative Council, the upper house of the New Zealand Parliament. In the end, however, Algie's proposal for a reworked Legislative Council were not pursued, and New Zealand's parliament has not had an upper house since that time.

Algie briefly returned to Opposition after the 1957 elections, which National lost. When National regained power in the 1960 elections, Algie is believed to have wanted the post of Minister of External Affairs, but was not appointed to it (possibly because of his age; he was seventy-two). Instead, he was convinced to take up the Speakership. He officially assumed office at the beginning of the 1961 parliamentary term.

As Speaker, Algie was known for his strong insistence on politeness in debates. He also undertook a number of reforms of Parliamentary procedures to accommodate the changing nature of politics. He served six years as Speaker, retiring at the 1966 elections. He was generally praised for his performance in the role, and had been given a knighthood in 1964.

Algie died in Auckland on 23 July, 1978.