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.
Valentina Tereshkova
Before her recruitment as a cosmonaut, Tereshkova was a textile-factory assembly worker and an amateur skydiver. After the dissolution of the first group of female cosmonauts in 1969, she became a prominent member of the Communist Party of the Soviet Union, holding various political offices. She remained politically active following the collapse of the Soviet Union and is regarded as a hero in post-Soviet Russia and much of the world. Having orbited Earth 48 times, Tereshkova remains the only woman ever to have been on a solo space mission.