James was born on 13 March 1939 in Kampung Karanaan, Tambunan, Sabah to a police officer, Alexius @ Alexander Ongkili Indoh, Snr.

(1910–1991), who hailed from the neighbouring village of Kampung Lintuhun (hitherto then was on home leave at the time of his birth after serving in the Royal Malaysia Police Sabah contingent headquarters, only to be reassigned in other districts such as Kota Marudu and Keningau, then known as the colonial North Borneo Constabulary in Kota Kinabalu), but later acquired land and settled in Keningau (in the village of Kampung Ria/Lingkudau) after his retirement from the police force and a housewife, Battindoi Kondilab Komboon (1915–1986), a native of the said village who was also a much older patrilineal female first cousin to Sabah politicians, Joseph Pairin Kitingan and his brother Jeffrey Gapari.

After completing his secondary education, he worked firstly as an untrained substitute teacher in St. John's School, Tuaran whilst waiting for his examination results.

But in March 1991, he announced that he joined the PBS, the party that was founded by his uncle, Joseph Pairin Kitingan.

[citation needed] He died at Queen Elizabeth Hospital, Kota Kinabalu on 20 March 2006, aged 67, just after a week celebrating his penultimate birthday and also his last 47th wedding anniversary.