William Ashby (12 January 1786 – 10 April 1847) was an English cricketer who played mainly for Kent teams. He was considered one of the best slow bowlers of his era and one of the pioneers of roundarm bowling. Ashby played his last first-class match in 1830, but continued to play club cricket. He was employed as a professional at the Clarence Cricket Club in Camberwell in 1836 and played there for 10 years. Ashby married Sarah Whatson in 1819 and had two children, a son and a daughter. He died of bronchitis at Lambeth in 1847 aged 61.