Leonard Ainsworth

Leonard Hasting "Len" Ainsworth AM (born 11 July 1923) is an Australian entrepreneur and philanthropist who founded two of the world's largest gambling-machine manufacturers: Aristocrat Leisure in 1953 and Ainsworth Game Technology in 1995. He began his career in his father's dental supplies business but pivoted to poker machine manufacturing, a side venture that grew into Aristocrat. Under his leadership, Aristocrat became a global market leader, controlling about 75% of the Australian poker machine market by the late 1970s.

After being diagnosed with prostate cancer in 1984, Ainsworth sold Aristocrat and initially retired. Following a clear diagnosis, he founded Ainsworth Game Technology in 1995, focusing on land-based casino machines. In 2018, at age 94, he sold a majority stake in AGT to Novomatic for A$473 million. He served as executive director of AGT until 2019, when he stepped down and retired.

Ainsworth has been a major philanthropist, supporting medical research, education, and the arts. He signed the Giving Pledge in 2017, committing at least 50% of his wealth to charity. He was appointed a Member of the Order of Australia (AM) in 2018. As of May 2025, his net worth was estimated at A$6.69 billion by the Financial Review Rich List.