Long was born March 4, 1874, in Honolulu, capital of the then-independent Kingdom of Hawaii.
His parents were Charles Long, an Italian immigrant from Milan, and Julia Naoho (1859–1916), a Native Hawaiian from the island of Maui and relative of historian Samuel Kamakau.
After his father's death, his mother remarried to John F. Colburn, who became a member of Queen Liliuokalani's cabinet during the final week before the Overthrow of the Kingdom of Hawaii in 1893.
He had many siblings and half-siblings from his mother's two marriages.

He received his early education at Saint Louis School and Punahou School (from 1892 to 1893), where he started playing football.
He graduated from Santa Clara University and later studied law at Stanford University and finished his law degree at Georgetown University.
Long was born March 4, 1874, in Honolulu, capital of the then-independent Kingdom of Hawaii. His parents were Charles Long, an Italian immigrant from Milan, and Julia Naoho (1859–1916), a Native Hawaiian from the island of Maui and relative of historian Samuel Kamakau. After his father's death, his mother remarried to John F. Colburn, who became a member of Queen Liliuokalani's cabinet during the final week before the Overthrow of the Kingdom of Hawaii in 1893. He had many siblings and half-siblings from his mother's two marriages.
He received his early education at Saint Louis School and Punahou School (from 1892 to 1893), where he started playing football. He graduated from Santa Clara University and later studied law at Stanford University and finished his law degree at Georgetown University.
Carlos A. Long