Route 56, also known as Kuhio Highway, is the main highway on the north and east shore of Kauaʻi island in Kauai County, Hawaii, United States.

Route 56 runs 28 miles (45 km), stretching from Hawaii Route 50 at the junction of Rice Street in Lihue to the junction of Hawaii Route 560 in Princeville on the island of Kauaʻi. The road is named for Prince Jonah Kūhiō Kalaniana'ole, a territorial delegate to Congress after the U.S. annexed Hawaii.

The road is a major thoroughfare for eastern and northern Kauaʻi. Leaving Lihue, the road passes the only Walmart and the major hospital on the island. It connects with Hawaii Route 51 to Lihue Airport. Following the intersection the road briefly passes through some rural patches with the occasional resort before crossing the Wailua River. At the Wailua River, there is a two-lane southbound bridge and a two-lane northbound bridge. A bridge expansion was completed in 2011. Going through Wailua and Kapaa, Hawaii 56 is jammed in the morning and the afternoon. Contra flow alleviates rush-hour traffic in the morning between Kapaa and Lihue Airport. The southbound lane gets two lanes in the morning to alleviate traffic pressures. Contra flow traffic starts at 6 a.m. on weekdays and 8 a.m. Saturday. Traffic is switched back to normal starting from the north at 11 a.m. weekdays and 1:30 pm on Saturday. The traffic pressure dissipates going through some of the countryside with few services and buildings from Kapaa heading toward Princeville. The bridge over the Kalihiwai river west of Kilauea is particularly scenic.

The entire route is in Kauai County.

Location	mi	km	Destinations	Notes
Lihue	0.0	0.0	Route 50 west	Southern terminus of Route 56; eastern terminus of Route 50
			Route 51 south	Northern terminus of Route 51
Wailua			Route 580 west	Eastern terminus of Route 580
Hanalei			Route 560 west	Western terminus of Route 56; eastern terminus of Route 560
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

• List of state highways in Hawaii
• List of highways numbered 56

• Roads of Kauai
• Photos of Kuhio Highway