East Petersburg is a borough in Lancaster County, Pennsylvania, United States. The population was 4,591 at the 2020 census.

Pennsylvania Route 72 is a 37.8-mile-long (60.8 km) north–south state route located in southeast Pennsylvania. The southern terminus of the route is at U.S. Route 222 /PA 272 in Lancaster. The northern terminus is at PA 443 north of Lickdale in Union Township. PA 72 serves as a major road connecting Lancaster and Lebanon counties, serving East Petersburg, Manheim, Cornwall, Lebanon, and Jonestown. The route intersects several major roads including US 30 and PA 283 north of Lancaster, the Pennsylvania Turnpike south of Cornwall, US 322 along a concurrency on a freeway bypassing Cornwall, US 422 in Lebanon, US 22 near Jonestown, and I-81 via Fisher Avenue in Lickdale.