Calvin Coolidge (born John Calvin Coolidge Jr.; ; July 4, 1872 – January 5, 1933) was an American politician and lawyer who served as the 30th president of the United States from 1923 to 1929. A Republican lawyer from New England, born in Vermont, Coolidge worked his way up the ladder of Massachusetts state politics, eventually becoming governor of Massachusetts. His response to the Boston Police Strike of 1919 thrust him into the national spotlight and gave him a reputation as a man of decisive action. The next year, he was elected vice president of the United States, and he succeeded to the presidency upon the sudden death of Warren G. Harding in 1923. Elected in his own right in 1924, he gained a reputation as a small government conservative and also as a man who said very little and had a rather dry sense of humor.

Coolidge restored public confidence in the White House after the scandals of his predecessor's administration, and left office with considerable popularity. As a Coolidge biographer wrote: "He embodied the spirit and hopes of the middle class, could interpret their longings and express their opinions. That he did represent the genius of the average is the most convincing proof of his strength".

Scholars have ranked Coolidge in the lower half of those presidents that they have assessed. He is praised by advocates of smaller government and laissez-faire economics, while supporters of an active central government generally view him less favorably, although most praise his stalwart support of racial equality.