St. John Bosco Seminary was established in 1967 by Bishop Cyprian Kihangire the founding Bishop of Hoima Diocese. The Seminary was began so as to give high school seminary priestly formation boys of secondary education.
After high school seminary the students go to Uganda's National Major Seminaries of either~ Alokolum Seminary (in Gulu Archdiocese) or ~ Katigondo Seminary (in Masaka Diocese) for B.A. Degree in pre-theologate priestly seminary formation.
After pre-theologate studies, the students go out to the parishes for one year of Pastoral-Spiritual Year. Then they go to either: Kinyamasika Seminary (in Fort Portal Diocese) or Ggaba Seminary (in Kampala Archdiocese) for 4 years of theologate seminary formation. St. Mbaga Seminary belongs to Kampala Archdiocese but also trains some seminarians from Hoima Diocese.