Jules-Pierre Mao is one of the owners of Mao-Kwikowski Mercantile, and also owns shares in Star Helix Security. He is the husband of Ariadne Mao, and together they had several children: Juliette Andromeda, Clarissa Melpomene, Petyr, and twins Michael and Anthea.
Mao is a handsome man with startling blue eyes. Middle-aged, he has a receding hairline that he chooses not to modify by medical therapies, giving him a dignified look.
Because his company was one of Protogen's major suppliers prior to the Eros incident, Mao and his wife were eager to recover their daughter Julie, who had become estranged and left Luna for the Belt to join the OPA, to save her from the war. Mao used his power and status as a shareholder in Star Helix Security to make them find her, kidnap her and send her back to Mao Station. This job fell on Captain Shaddid, head of the police force on Ceres, where Julie lived. She put Detective Miller on the case, who was ultimately unsuccessful.
During the aftermath of the Eros incident, Mao and his company argued they didn't know what their equipment was used for, and no evidence was found to implicate them.
After the Ganymede incident Jules-Pierre has a meeting with the United Nations Assistant Undersecretary of Executive Administration, Chrisjen Avasarala. During the meeting Avasarala tries to pry any information about Venus he may have left out of the hearings of Protogen but he denies giving a calm sense of professionalism.
His daughter Clarissa Mao vowed to avenge him by destroying Holden.