It stretches for just over 20 miles (32 km) from its southern terminus in northern Alliance where it meets State Route 183 to its northern terminus at State Route 5 opposite the Ravenna Training and Logistics Site in Paris Township.

The road is two lanes almost the entire length, except for the portion at the partial interchange with the future U.S. Route 62 just north of the Alliance city limits.

It crosses Interstate 76 at exit 48 in Palmyra Township just north of its intersection with Tallmadge Road (County Road 18), formerly designated as State Route 18.

State Route 225 was first designated in 1924, though initially it ran along part of what is now Alliance Road in Portage County, extending from the current U.S. Route 224 to the south and ending at State Route 14 in the small town of Yale to the north.

[4][5] By 1937, it was again rerouted and extended, returning to its original location to Yale, but this time going 3 miles (4.8 km) further north to State Route 18, and extending south to Alliance along its current alignment south of U.S. Route 224.