Thelma Thall "Tybie" Sommer (born March 12, 1924) is the only living American woman to have won two World Table Tennis Championships.

[5] In 1948, Thall and Richard Miles were the first Americans to win the World's Mixed Doubles Title, in Wembley, London, England.

[6] In 1949, Thall, as a member of the USA Team, won Singles and Doubles in the Corbillon Cup, a World Championship Event, in Stockholm, Sweden.

[12] In 2012, she presented "The Thall Sisters Cup", a newly-created trophy to the winner of the Women's Singles in the U.S. Open Table Tennis Championships.

This perpetual trophy lists the winners from 1933 to the present (sister Leah won the US Open 9 times and the World's once; Thelma won the World's twice); while the winner each year gets a small replica, the original sits at the Olympic Training Center in Colorado Springs, Colorado.