William Maivia is a fictional 24th century Starfleet officer.

William was born on Oahu, Hawaii, Earth in 2342 and is Somoan (native hawaiian). At an early age, William enjoyed playing various sports and swimming, which made him a very strong and athletic individual. At the age of 17, William decided that he wanted to set out and explore the galaxy and applied to Starfleet Academy in 2361. There, he studied Security and Tactical. He also qualified with Starfleet's major shuttlecraft models. In 2363, William graduated from Starfleet Academy and was assigned to the USS Enterprise-D under the command of Captain Jean-LucPicard as a security officer. While there, he was promoted to Lt j.g. and reassigned to the USS Monitor as the Assistant Security Officer in 2368 being promoted to lieutenant upon successfully saving the captain's life during an Away mission. While there, William decided he wanted a command someday so he took the required Command and Operation Courses. In 2372, he was reassigned to Starbase 57 as Operations Officer and promoted to Lieutenant Commander. He was then assigned to the USS Saratoga in 2374 and fought in the Dominion War. While there, he served with distinction, during the battle of the Chintoka System, he took command of the Saratoga during a battle in which the captain was badly wounded and was promoted to Commander. After the war, he was again commendated for saving the Captain's life on an away mission. He was then reassigned to the USS Indianapolis to become the First Officer and soon after became the CO of the USS Indianapolis.

Currently, Rear Admiral Maivia serves as Task Force 38's Executive Officer while retaining his command of USS Indianapolis (NCC-77173-A).