Katherine McDonald Wimp née Katherine McDonald stage name Kay Davis (December 5, 1920 – January 27, 2012 in Apopka, Florida) was an American jazz singer best known for her time with the orchestra of Duke Ellington.
Davis was born in Evanston, Illinois and attended Evanston Township High School before she studied voice and piano at Northwestern University, where she received her bachelor's degree in 1942 and her masters in 1943. Her grandfather, William H. Twiggs, was a civic leader for whom a park in Evanston is named.
In 1944 she joined Duke Ellington's orchestra, where she sang alongside Joya Sherrill and Al Hibbler. She is best known for her wordless vocals in pieces such as "Transblucency" and "On a Turquoise Cloud". She also sang many pieces with lyrics. She is the only person Ellington allowed to reprise Adelaide Hall's famous wordless vocal on "Creole Love Call". Her tenure in Ellington's band coincided with their increasing exposure on film, especially for Universal Pictures. Davis and Billy Strayhorn gave the first performance of Strayhorn's "Lush Life" on November 13, 1948 at Carnegie Hall—even though the song had been written in the 1930s.
She toured England with Ellington and Ray Nance in 1948 and in Europe with the full orchestra in 1950. After leaving Ellington's orchestra in 1950, she married Edward Wimp, and later retired to Florida.