The Progressive party was the name for three separate political organizations in U.S. history. Although the 1912, 1924, and 1948 organizations were all concerned with social reform and were generally opposed to excessive corporate power, they differed substantially in their emphases.

The Progressive party of 1912 grew out of former President Theodore Roosevelt's drive for the Republican presidential nomination. Foiled by the incumbent, William Howard Taft, who controlled the convention machinery, Roosevelt led his supporters into his Bull Moose Party (another name for the Progressives). The party's 1912 platform called for numerous social and political reforms, including the conservation of natural and human resources, Women Suffrage, popular election of U.S. senators, and the initiative, referendum, and recall. Roosevelt campaigned zealously but could not defeat the progressive Democratic candidate, Woodrow Wilson; still, Roosevelt and his vice-presidential candidate, Hiram Warren Johnson, polled 4.1 million votes--about 600,000 more than Taft received. In 1916, with World War I under way in Europe, Roosevelt and most of his followers crusaded for war preparedness, delivering the Progressive nomination to the Republican candidate, Charles E. Hughes, and shattering their own weakened party.