Sennett Bathing Beauties was a bevy of women performing in bathing costumes assembled by film producer Mack Sennett. They appeared in comedy short subjects, in promotional material, and in promotional events such as Venice Beach beauty contests from ca 1915 - 1928. Beginning in 1915, the original trio assembled by Sennett consisted of Evelyn Lynn, Cecile Evans, and Marie Prevost  Hundreds more would follow; many remained nameless.
Not individually featured or named, many of these young women ascended to significant careers of their own, including Juanita Hansen, Claire Anderson, Marie Prevost, Phyllis Haver, Myrtle Lind and Carole Lombard. Other notable Bathing Beauties include: Marion Aye, Alice Day, Polly Moran, Madeline Hurlock, Vera Reynolds, Mary Thurman, Thelma Hill, Thelma Parr, Marvel Rea, Harriet Hammond, Evelyn Francisco, Vera Steadman, Josephine Cogdell, Elinor Field, and Ora Carew.
Two of those often named as Bathing Beauties later distanced themselves from the appellation: Mabel Normand and Gloria Swanson. Normand was a featured player, and her 1912 8-minute film The Water Nymph may have been the direct inspiration for the Bathing Beauties. Although Gloria Swanson worked for Sennett in 1916 and was photographed in a bathing suit, she was also a star and "vehemently denied" being one of the bathing beauties.
One morning as I went through the Times, in my tub, I noticed a three-column picture on Page One of a pretty girl who had been involved in a minor traffic accident. The picture made the front page for two obvious and attractive reasons. The young lady's knees were showing.— Mack Sennett, King of Comedy 
In the 1920s, Sennett's Bathing Beauties remained popular enough to provoke imitators such as the Christie Studios' Bathing Beauties (counting Raquel Torres and Laura La Plante as alumnae) and Fox Film Corporation's "Sunshine Girls" (counting Janet Gaynor as an alumna). The Sennett Bathing Beauties continued to appear through 1928.
- "Splashes of Fun and Beauty" by Hilde d'Haeyere, collected in Slapstick Comedy by Rob King, p.205.
- "Hollywood's Bathing Beauties". Lapham’s Quarterly.
- "notable" in this context refers to the fact only notable subjects get their own Wikipedia article (i.e. the links and their references confirm the notability of each subject). Josephine Cogdell included because of her connection to Philippa Schuyler
- "Josephine Cogdell as a pin-up girl, during the period she was a Mack Sennett bathing beauty, 1919". NYPL Digital Collections.
- Balshofer, Fred J. & Miller, Arthur C. One reel a week, p.81.
- Jeanine Basinger, Jeanine. Silent Stars, p.205.
- King of Comedy, 1954, page 167 by Mack Sennett, Cameron Shipp
- Lowe, Denise. An encyclopedic dictionary of women in early American films, 1895-1930, p.308.
- King, Rob. The fun factory: the Keystone Film Company and the emergence of mass culture, p.211.