Leleiohoku was the youngest brother of Nobile Moses Kapaakea, Prince James Kaliokalani, King David Kalakaua, Queen Lili'uokalani, Princess Anna Kaiulani, Princess Kaiminaauao, Prince Kinini Kapaakea, and Princess Miriam K. Likelike. At birth he was hanaied (adopted) by Princess Ruth Keelikolani and she named him after her late husband High Chief William Pitt Leleihoku I. He was also her heir to her vast holding of most of the Kamehameha lands but he predeceased her. He was educated at Saint Alban's College. An accomplished musician, he founded several royal choral societies that survive today including the Kawaiha'o Singing Club. He was named the Crown Prince by his brother Kalakaua when he ascended to the throne with the consent of House of Nobles and granted the title of Prince and style of His Royal Highness. He later became a member of the House of Nobles and also ruled as Prince-regent in the absence of Kalakaua when he visited the United States.
Death
On April 10, 1877 at the age of 23, Prince Leleiohoku died of rheumatic fever. Because Leleihoku was unmarried and left no issues, his brother King Kalakaua named their sister Liliuokalani, Crown Princess. It was said that Princess Keelikolani had wished that Kalakaua had chosen her instead of Liliuokalani but making her heir would make Princess Bernice Pauahi Bishop next in line to the throne.