With the 20th century's movie industry making many women (and men) into well-known celebrities, and the "star system" extended into other fields such as sports as well. It was only natural that some stars would find ways to use their celebrity to support the war effort.
In Germany, Hitler used propaganda to support his war effort. Actress, dancer, and photographer Leni Riefenstahl made documentary films for the Nazi Party during the 1930s and Hitler's consolidation of power. She escaped punishment after the war after a court found that she was not herself a Nazi party member.
In America, films and plays promoting participation in the war and anti-Nazi films and plays were also part of the overall war effort. Women actresses played in many of these. Women also wrote some of them: Lillian Hellman's 1941 play, The Rhine, warned of the rise of the Nazis.
Entertainer Josephine Baker worked with the French Resistance and entertained troops in Africa and the Middle East. Alice Marble, a tennis star, secretly married an intelligence operative and when he died, was convinced to spy on a former lover, a Swiss banker, suspected of having records of Nazi finances. She found such information, and was shot in the back, but escaped and recovered. Her story was told only after her death in 1990.
Carole Lombard made her final film as a satire about the Nazis, and died in a plane crash after attending a war bond rally. President Franklin D. Roosevelt declared her the first woman to die in the line of duty in the war. Her new husband, Clark Gable, enlisted in the Air Force after her death. A ship was named in Lombard's honor.
Perhaps the most famous pin-up poster in World War II showed Betty Grable in a swimsuit from the back, looking over her shoulder. The Varga Girls, drawn by Alberto Vargas, were also popular, as were photos of Veronica Lake, Jane Russell, and Lane Turner.
In New York's theater world, Rachel Crothers started the Stage Women's War Relief. Others who helped to raise funds for war relief and the war effort included Tallulah Bankhead, Bette Davis, Lynn Fontaine, Helen Hayes, Katharine Hepburn, Hedy Lamarr, Gypsy Rose Lee, Ethel Merman, and the Andrews sisters.
The USO Tours or Camp Shows which entertained troops in the US and overseas drew many women entertainers, too. Rita Hayworth, Betty Grable, the Andrews Sisters, Ann Miller, Martha Raye, Marlene Dietrich, and many lesser-knowns were welcome relief for the soldiers. Several "all-girl" bands and orchestras toured, including the International Sweethearts of Rhythm, one of the rare racially-mixed groups.