Astronaut
The first civilian in space was Valentina Tereshkova aboard Vostok 6 (she also became the first woman in space on that mission).
Tereshkova was only honorarily inducted into the USSR's Air Force, which did not accept female pilots at that time. A month later, Joseph Albert Walker became the first American civilian in space when his X-15 Flight 90 crossed the line, qualifying him by the international definition of spaceflight. Walker had joined the US Army Air Force but was not a member during his flight. 
The first people in space who had never been a member of any country's armed forces were both Konstantin Feoktistov and Boris Yegorov aboard Voskhod 1.
Margaret Rhea Seddon
Margaret Rhea Seddon (born November 8, 1947) is a physician and retired NASA astronaut. After being selected as part of the first group of astronauts to include women, she flew on three Space Shuttle flights: as mission specialist for STS-51-D and STS-40, and as payload commander for STS-58. Both before and after her career in the astronaut program, she has been active in the medical community in Tennessee, Mississippi and Texas.