Born Kathryn Jewel Thorne on January 11, 1936 in Houston, Texas, Webster first learned piano as a child. Her deeply religious parents strictly warned her to play only gospel and classical music, going so far as to keep the piano under lock and key so Katie could only play while being supervised. But Webster loved the blues, rock and R&B she heard on an old Philco radio hidden under the bed covers late at night, and would play her secular music at every opportunity. While still a teenager, Webster moved to South Louisiana when her parents relocated to California. She lived with less rigid relatives who allowed her to play the music she loved. By the age of 15 Webster was one of the most requested studio musicians in the region. Both Jay Miller of Excello Records and Eddie Shuler of Goldband Records used her on hundreds recordings in the 1950s and 1960s, including sides with Guitar Junior (Lonnie Brooks), Slim Harpo, Lazy Lester, Lightnin' Slim, and Clifton Chenier. In 1964, a young Otis Redding caught Webster's set with her band the Uptighters in Lake Charles, Louisiana, and demanded she join his touring band the very next day.
Webster toured the country with Redding, and can be heard on his Live At The Whiskey A-Go-Go album. Unable to join Redding on tour in 1967 because she was pregnant, Webster was not on the plane that took Redding's life. Devastated by his death, she kept a very low profile until the early 1980s, when she made her debut tour of Europe. European audiences couldn't get enough of Webster, and she returned over 30 times. During the 1980s, Webster began to win over her American audience at numerous high profile festival gigs, including the Chicago Blues Festival, The New Orleans Jazz and Heritage Festival, The Boulder Blues Festival, The Newport Folk Festival, The San Francisco Blues Festival and many others. "She can floor the timid listener," raved the Boston Globe. "Webster can say more about the pain of betrayal with one low, sad growl, and more about the joy of fighting back against cruel life with one teasing roll of her eyes, than most could write in a book."
In 1988, Webster teamed up with Alligator Records and went from a cult blues legend to internationally recognized phenomenon. She received accolades from a host of publications, including Rolling Stone and Keyboard. She was nominated for three Blues Music Awards (the Grammy of the blues community) and, in March of 1989, performed for the first time on national television on NBC's Sunday Night program hosted by David Sanborn. In 1992, Webster joined label mates Koko Taylor, Lonnie Brooks, Elvin Bishop and Lil' Ed and the Blues Imperials on a cross-country tour celebrating Alligator's 20th Anniversary. The Alligator Records 20th Anniversary Tour album documented the proceedings, as did the Bob Mugge documentary, Pride And Joy: The Story Of Alligator Records.
In 1993, Webster was felled by a stroke while touring in Greece, and lost some of the use of her left hand and almost all of her eyesight. But her magnificent voice and wonderful right hand, not to mention her inimitable spirit, kept her going strong. She continued to appear at selected festivals. Even though her health wouldn't support extended touring, her final performances were filled with the same boogie-woogie drive and spirit that originally earned Katie Webster the title Swamp Boogie Queen.