New Jersey State Highway 29 is a state highway in New Jersey, United States. It runs from an intersection with Interstate 295 in Hamilton Township, New Jersey (where it continues as Interstate 195) to Bridge Street/Race Street in Frenchtown, New Jersey. (See Interstate 95.)

The sceneic and mostly two-lane highway follows the Delaware River in mostly rural sections of Mercer County and Hunterdon County. The obsolete Delaware & Raritan Canal usually stands between the river and the highway. Most sections of Route 29 are completely shaded due to the tree canopy.

In Trenton, New Jersey, the road is a near-freeway in some sections, including a tunnel that was built along the river near historic houses and a cemetery. Traffic pauses for a signal at Cass Street, next to Mercer County Waterfront Park. The road is again a freeway as it passes the state capitol, but it then narrows into the two-lane road mentioned above.

In Lambertville, New Jersey, officially, both directions of NJ 29 run down South Main Street. Nevertheless, South Main Street is one-way southbound for a bit. So, the northbound traffic empties onto secret New Jersey State Highway 165, which goes north to the point where traffic can once again go northbound on NJ 29; the signs there say "TO NJ 29".