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.
Kathryn D. Sullivan
Kathryn Dwyer Sullivan (born October 3, 1951) is an American geologist and a former NASA astronaut. A crew member on three Space Shuttle missions, she was the first American woman to walk in space on October 11, 1984. She was Under Secretary of Commerce for Oceans and Atmosphere and Administrator of the National Oceanic and Atmospheric Administration after being confirmed by the U.S. Senate on March 6, 2014. Sullivan's tenure ended on January 20, 2017 with the swearing in of President Donald Trump. Following completion of her service at NOAA, she was designated as the 2017 Charles A. Lindbergh Chair of Aerospace History at the Smithsonian Institution’s National Air and Space Museum., and has also served as a Senior Fellow at the Potomac Institute for Policy Studies.