Sophie Mary Wilson (born Roger Wilson; June 1957) is an English computer scientist, a co-designer of the instruction set for the ARM architecture.

Wilson first designed a microcomputer during a break from studies at Selwyn College, Cambridge. She subsequently joined Acorn Computers and was instrumental in designing the BBC Microcomputer, including the BBC BASIC programming language. She first began designing the ARM reduced instruction set computer (RISC) in 1983, which entered production two years later. It became popular in embedded systems and is now the most widely used processor architecture in smartphones. In 2011, she was listed in Maximum PC as number 8 in an article titled "The 15 Most Important Women in Tech History". She was made a Commander of the Order of the British Empire in 2019.

Wilson was born in Leeds to schoolteacher parents, her father specialising in English and her mother in physics. She spent her childhood in the village of Burn Bridge, North Yorkshire. After secondary schooling at Harrogate Grammar School, in 1976 Wilson went up to Selwyn College, Cambridge, where she studied mathematics for her first two years, switching to computer science in her final year. She was a member of the university Microprocessor society.

Before going to university, Wilson had designed and built two electronic systems for ICI Fibres Research in Harrogate near her home village. The following year, in the 1977 summer vacation after her first year at university, she designed a small system around a MOS Technology 6502 microprocessor, which was used to electronically control feed for cows.

Wilson's success with the cow-feeder project and paper designs for a more general system based on it caught the notice of Hermann Hauser, at the time a Cambridge postgraduate student. Hauser was impressed, and supported Wilson to stay in Cambridge for the 1978 summer vacation to see if she could turn the design into reality. At the same time a small microcomputer kit, the MK14, was just being launched by Science of Cambridge, led by Chris Curry on behalf of Cambridge electronics businessman Clive Sinclair. Wilson was convinced she could do better, and Hauser encouraged her to do so, using parts from the MK14.

In December 1978 Hauser and Curry set up Cambridge Processor Unit Ltd (CPU), initially as a consultancy designing microprocessor-based control systems. Their first customer was Ace Coin Equipment Ltd, who needed controllers for their fruit machines, with Wilson designing a device to prevent cigarette lighter sparks triggering payouts. Meanwhile Wilson's computer design, combined with a cassette interface designed by Steve Furber, became the Acorn Micro-Computer, the first of a long line of computers sold by the company. Wilson started at the company in 1979.

Based on this processor board, CPU Ltd developed an increasing number of different interface, display, control, and test add-ons for different customers, which in turn led to the Acorn Eurocard rack systems that were made generally available, and then the Acorn Atom released in March 1980. Wilson, initially moonlighting from the final year of her degree, contributed first the machine code monitor, then an assembler, then a version of BASIC and multiple device drivers for the machines ("an incredible task of bootstrapping things up"), as well as pitching in with everything else in the office.

Wilson was at the forefront of creating the prototype that enabled Acorn to win the contract with the British Broadcasting Corporation (BBC) for their ambitious computer education project.