John Leys (January 27, 1834 – February 17, 1900) was an Ontario lawyer and political figure.

He represented Toronto in the Legislative Assembly of Ontario from 1886 to 1890 as a Liberal member.

He was born in Pickering, Ontario County, Upper Canada in 1834, the son of Francis Leys, a Scottish immigrant.

Leys studied law with Angus Morrison, was called to the bar in 1860 and set up practice in Toronto.

He ran unsuccessfully in Toronto East in 1882 before his election to the provincial assembly in 1886.