Stewart John Greenleaf Sr. (October 4, 1939 – February 9, 2021) was an American politician and attorney who served as a member of the Pennsylvania State Senate from 1979 to 2019.

Greenleaf considered a run for U.S. Congress in 1993, briefly forming an exploratory committee to challenge Marjorie Margolies.

[5] He filed with the FEC on December 29,[6] and received a total of 24 votes in the primary, 21st place amongst ballot candidates.

Including other write-ins, this tied him with Mitt Romney for third place in the town, behind only Barack Obama and Ron Paul.

[8] Greenleaf died at Holy Redeemer Hospital in Meadowbrook, Pennsylvania, on February 9, 2021, at age 81.