William Lockhart may refer to:

• William Lockhart of Lee (1621–1675), Oliver Cromwell's ambassador at Paris
• William Lockhart (surgeon) (1811–1896), medical missionary and fellow of the Royal College of Surgeons
• William Lockhart (priest) (1820–1892), English Roman Catholic priest, convert from Anglicanism
• Sir William Lockhart (Indian Army officer) (1841–1900), British Indian Army general
• William Ewart Lockhart (1846–1900), Scottish Victorian painter
• William Mustart Lockhart (1855–1941), Scottish topographical painter
• William Thomas Lockhart (born 1839), Ontario merchant and political figure
• William Lockhart (MP) (1787–1856), British member of parliament for Lanarkshire