Oscar F. Thieme (May 28, 1869 – 1926) was an American businessman and politician from Milwaukee, Wisconsin.
He served one term as a member of the Wisconsin State Assembly.
He worked in real estate and insurance, and, for a time, was employed as a clerk for Milwaukee County judges Emil Wallber, James M. Pereles, and John E. Mann.
He was elected to the Assembly as a Republican, representing Milwaukee County's 8th district (the 9th ward of the city of Milwaukee) in a three-way race, defeating Democrat David Geraghty and Social Democrat William Baumann.
[1] He died in 1926 and was buried at Milwaukee's Forest Home Cemetery.