Mildred Bailey (born Mildred Rinker; February 27, 1907 – December 12, 1951) was an American jazz singer during the 1930s and 1940s, known as "The Queen of Swing", "The Rockin' Chair Lady", and "Mrs. Swing".

She recorded the songs "For Sentimental Reasons," "Georgia on my Mind," "St. Louis Blues," "It's So Peaceful in the Country," "Doin' The Uptown Lowdown," "Trust in Me," "Where Are You?," "I Let a Song Go Out of My Heart," "Small Fry," "Please Be Kind," "Darn That Dream," "Rockin' Chair," "Blame It on My Last Affair," and "Says My Heart." She had three records that reached number one on the popular charts.

Bailey grew up on the Coeur d'Alene Reservation in Idaho, where her mother was an enrolled citizen. The family moved to Spokane, Washington, when she was 13. Her younger brothers also became musicians. Her brother, Al Rinker, started to perform as a singer with Bing Crosby in Spokane and became a member of The Rhythm Boys. As adults, Charles Rinker was a lyricist, and Miles Rinker was a clarinet and saxophone player who later became a booking agent.

Bailey was born Mildred Rinker on a farm in rural Tekoa, Washington. Her mother Josephine was a citizen of the Coeur d'Alene Tribe and a devout Roman Catholic. Bailey's great-grandfather, Bazil Peone, was a head speaker and song leader of the Coeur d'Alene at the turn of the 20th century. His ability to create indigenized Catholic hymns helped guide the tribe during difficult times of active colonization by Jesuit missionaries.

Bailey and her siblings grew up near De Smet, Idaho, on the Coeur d'Alene Reservation. Her father played fiddle and called square dances. Her mother played piano every evening and taught her to play and sing. Her younger brothers included Miles, Al, a vocalist and composer, and Charles, a lyricist. The family often hosted Saturday night gatherings, creating small music and dance hall in the home for local ranchers with both Josephine and Mildred at the piano. Mildred also accompanied her mother to traditional native ceremonies, where she heard and practiced the traditional songs and lyrics that would later influence her unique singing voice.

Josephine died from tuberculosis at the age of 36, threatening Mildred's ability to remain connected to her native family and traditions in a way that she was able to while her mother was alive. Soon after Josephine's death, Mildred's father remarried, bringing a daughter and creating a tumultuous and unhappy house from which Mildred and her siblings were systematically pushed out by her new stepmother. Given an ultimatum to choose his own children or his new wife, Mildred's father sided with his wife and Mildred moved out of the home and in with her aunt and uncle in Seattle. She and her aunt were involved in a serious car accident a short time later which killed her aunt and left Mildred with serious physical and emotional scars.

At age 17, Rinker moved to Seattle and worked as a sheet music demonstrator at Woolworth's. She married and divorced Ted Bailey, keeping his last name because she thought it sounded more American than Rinker, which was of Swiss (German) origin.

She toured with a West Coast revue and finished in California where she obtained work at radio station KMTR and at a speakeasy in Bakersfield called The Swede's. With the help of her second husband Benny Stafford, Bailey became an established blues and jazz singer on the west coast of the United States. According to Gary Giddins in his book Bing Crosby: A Pocketful of Dreams, The Early Years 1903–1940, she found work for her brother Al Rinker and Bing Crosby, who had started performing in Spokane, Washington. They had traveled from Spokane to join her in Los Angeles. Giddins says Crosby heard about Louis Armstrong from Bailey, who urged him to hear Armstrong if Crosby was to be a serious jazz singer. She also played Crosby records from her collection by Ethel Waters and Bessie Smith.