State Route 129 (
SR 129) is an east–west highway in southwest Ohio running from its western terminus at
SR 126, just east of the
Indiana/
Ohio state line near
Scipio, Ohio. Its eastern terminus is at
I-75 in
Liberty Township. The route's eastern terminus was historically at
State Route 747 until 1999 when the route was moved south ½ mile to the newly built Butler County Veterans Highway.