William Maclay

• William Maclay (Pennsylvania politician, born 1737), United States Senator from Pennsylvania
• William Maclay (Pennsylvania politician, born 1765), United States Representative from Pennsylvania
• William Plunkett Maclay, United States Representative from Pennsylvania, nephew of the senator
• William B. Maclay, United States Representative from New York
• William P. Maclay (Medal of Honor), Philippine Insurrection Medal of Honor recipient