Helen Patricia Sharman (born 30 May 1963) is a British chemist and cosmonaut who became the first British person, first Western European woman and first privately funded woman in space, as well as the first woman to visit the Mir space station, in May 1991.

Sharman was born in Grenoside, Sheffield, where she attended Grenoside Junior and Infant School, later moving to Greenhill. After studying at Jordanthorpe Comprehensive, she obtained a BSc degree in chemistry at the University of Sheffield in 1984 and a PhD degree from Birkbeck, the University of London in 1987. She worked as a research and development technologist for GEC in London and later as a chemist for the American confectioner Mars, dealing with the flavouring properties of chocolate. This later led the UK press to label her "The Girl from Mars".

After responding to a radio advertisement asking for applicants to be the first British space explorer, Sharman was selected for the mission live on ITV, on 25 November 1989, ahead of nearly 13,000 other applicants. She was commuting home from work when she heard the radio advertisement. “Astronaut wanted. No experience necessary.” The programme was known as Project Juno and was a cooperative Soviet–British mission co-sponsored by a group of British companies. Its aim was to enhance the relationship between the UK and the Soviet Union in the twilight years of the Cold War by sending a British astronaut to the Mir space station.

Sharman was selected in a process that gave weight to scientific, educational and aerospace backgrounds, as well as the ability to learn a foreign language.

Sharman would later recall that she was more excited about the training than the flying itself, stating “It wasn’t so much going to space as the training that appealed, living in Russia, learning the language, doing advanced mechanics. It was a way out of the rat race.” Before flying, Sharman spent 18 months in intensive flight training in Star City, Moscow. She trained alongside her British back-up Major Tim Mace. The Project Juno consortium failed to raise the money expected, and the programme was almost cancelled. With a view toward the flight's impact on international relations, the project proceeded at Soviet expense although as a cost-saving measure, less expensive experiments were substituted for those in the original plans.

The Soyuz TM-12 mission, which included Soviet cosmonauts Anatoly Artsebarsky and Sergei Krikalev, launched on 18 May 1991 and lasted eight days, most of that time spent at the Mir space station. Sharman's tasks included medical and agricultural tests, photographing the British Isles, and participating in a licensed amateur radio hookup with British schoolchildren. She landed aboard Soyuz TM-11 on 26 May 1991, along with Viktor Afanasyev and Musa Manarov. On the launch day, Sharman had a "space passport" with her in case they had to land outside Russia. She had also carried with her a butterfly brooch her father had given her and a photo of Queen Elizabeth II.

Sharman was 27 years and 11 months old when she went into space, making her (as of 2017^[update]) the sixth youngest of the 556 individuals who have flown in space. Sharman has not returned to space, although she was one of three British candidates in the 1992 European Space Agency astronaut selection process and was on the shortlist of 25 applicants in 1998.

Since Juno was not an ESA mission, Tim Peake became the first ESA British astronaut more than 20 years later.