Spencer Beach Park is a county park named for Hawaiʻi island politician Samuel Mahuka Spencer (1875–1960).
Spencer was born in the area in 1875, and died on February 28, 1960. He was named for Samual Mahuka who was a judge in the area from 1893 to 1901. He served as the chairman and executive officer of the Hawaii County Board of Supervisors 1924–1944, and some minor offices in the Territory of Hawaii. In 2003 the park was renamed to include the original name of the beach, ʻŌhai ʻula. The beach could have been named for the red Sesbania tomentosa trees that originally grew in the area, or the royal poinciana tree Delonix regia.
The Samuel M. Spencer Beach Park in the Kohala area of the Big Island of Hawaii is a favorite camping and snorkeling location. On July 18, 1935 Spencer planted one of the banyan trees lining the "Hilo Walk of Fame" on Banyan Drive. As county chairman Spencer was responsible for some of the access improvements to the Waipiʻo Valley. He was postmaster in the area, which is why some sources say the post office for Waimea, Hawaii County, Hawaii is called "Kamuela", the equivalent of Samuel in the Hawaiian language. The beach is a terminus for a segment of the Southern Cross Cable, the major Submarine communications cable connecting to the island.