Pennsylvania Route 225 is a 48.5-mile-long (78.1 km) state highway located in Dauphin and Northumberland Counties in Pennsylvania. The southern terminus is at an interchange with U.S. Route 22 /US 322 in Dauphin. The northern terminus is at PA 61 in Shamokin. PA 225 is mostly a two-lane undivided road running through mountain and valley areas in the central part of the state. The route serves the communities of Halifax, Elizabethville, Berrysburg, Pillow, and Trevorton. PA 225 intersects PA 325 north of Dauphin, PA 147 in Halifax, US 209 in Elizabethville, PA 25 in Berrysburg, and PA 890 in Trevorton.

Dauphin County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 286,401. The county seat is Harrisburg, Pennsylvania's state capital and ninth-most populous city. The county was created on March 4, 1785, from part of Lancaster County and was named after Louis Joseph, Dauphin of France, the first son of King Louis XVI. The county is part of the South Central Pennsylvania region of the state.