His father, who was a devout Christian, died when Adetiloye was aged 3 years old, and he and his siblings were raised by his mother.
He was ordained a deacon at the end of 1953 at the Cathedral Church of Lagos, by the first Archbishop of West Africa, Leslie Vining.
Returning to Nigeria, the Adetiloye was a teacher at the Immanuel College of Theology in Ibadan, for four years and three months.
Archbishop Adetiloye headed the Province One, consisting of the dioceses in the West, while remaining Primate of All Nigeria.
His tenure is described by Elijah Olu Akinwumi: "His passion for evangelism and missions motivated him to judiciously mobilize financial resources from the Lagos diocese: directly, by challenging men to give and leading by his example; indirectly, by encouraging wealthy parishes to support seemingly weak ones or even planting new churches or opening a new diocese as the case may be.