Ohio State Route 66

State Route 66
Route of SR 66 highlighted in red
Route information
Maintained by ODOT
Length	118.60 mi[1] (190.87 km)
Existed	1924–present
Major junctions
South end	US 36 in Piqua
Major intersections	US 33 in St. Marys US 30 near Delphos US 224 in Ottoville US 24 near Defiance US 6 near Evansport I-80 / I-90 / Ohio Turnpike near Archbold
North end	US 20 in Fayette
Location
Country	United States
State	Ohio
Counties	Miami, Shelby, Auglaize, Allen, Van Wert, Putnam, Paulding, Defiance, Williams, Henry, Fulton
Highway system
Ohio State Highway System Interstate US State Scenic
← SR 65 → SR 67

State Route 66 (SR 66) is a north–south state highway in the northwestern portion of the U.S. state of Ohio. Its southern terminus is at U.S. Route 36 (US 36) in Piqua, and its northern terminus is at US 20 in Fayette. South of Defiance it generally follows the route of the former Miami and Erie Canal.