U.S. military service group, founded in 1942 for the purpose of making more men available to serve at sea by assigning women to onshore duties during World War II.

During World War I the U.S. Coast Guard (United States Coast Guard) enlisted a small number of women to serve as volunteers, primarily in clerical roles. During World War II, on November 23, 1942, President Franklin D. Roosevelt signed a law that established the Coast Guard Women's Reserve. The women reservists served under the leadership of Lieutenant Commander Dorothy Stratton (Stratton, Dorothy Constance). They were not permitted to serve beyond the boundaries of the continental United States or to give orders to any male serviceman, although both these rules were relaxed over time as women began to take on roles of greater responsibility. The Women's Reserve came to be referred to as the SPARS, an acronym representing the Coast Guard motto, “Semper Paratus—Always Ready.”

After the end of World War II, the SPARS were demobilized. While a small number of women volunteered again during the Korean War, the Coast Guard did not actively pursue an enlistment drive for the SPARS during either that conflict or the Vietnam War. In 1973 Congress enacted legislation that terminated the SPARS as a separate branch of the Coast Guard and thus made women eligible to serve alongside men in both regular and reserve units of the Coast Guard. In late 1977 women were first permitted to serve aboard seagoing Coast Guard vessels.