County Route 520, abbreviated CR 520, is a county highway in the U.S. state of New Jersey. County Route 520 is a major road across Monmouth County connecting the county's central towns to the Jersey Shore at Sea Bright.

The highway extends 22.39 miles (36.03 kilometers) from Englishtown Road (CR 527) in Old Bridge Township to Ocean Avenue (Route 36, formerly County Route 9) in Sea Bright.

CR 520 extends east along Texas Road to the intersection with Marlboro Road, then turns southeast onto Marlboro Road. Texas Road continues beyond Marlboro Road as CR 690. CR 520 is under municipal (Old Bridge and Marlboro Townships) jurisdiction between Texas Road and US 9. From US 9 to its eastern terminus it is under Monmouth County jurisdiction. CR 520 is known by several names between US 9 and NJ 35, among them Main Street, Newman Springs Road and simply Route 520, but for the greater part of its distance it is Newman Springs Road. At NJ 35 CR 520 turns briefly north on Broad Street in Red Bank, then turns east again onto Pinckney Road, which it follows into Little Silver. It continues through Little Silver along Branch Avenue before turning onto Rumson Road, which it then follows through Rumson to its terminus at Ocean Avenue (NJ 36) in Sea Bright.

The western terminus of 520 is somewhat unclear. According to NJDOT documents, 520 begins at the intersection with CR 527. According to NAVTEQ, 520 starts at the townline with Old Bridge Township and Monroe Township (which would increase the length to 23.09). However, TeleAtlas indicates that 520 traverses into Monroe Township, and ends at CR 613 (along Texas Road, not Matchaponix Road Extension, which would increase the length to 24.19). CR 520 eventually turns into Middlesex CR 612 after its western end, which in turn leads to Exit 8A of the New Jersey Turnpike in Monroe Township. Middlesex County jurisdiction begins at CR 527.