He grew up in Nyakemicha Village in Nyamira County, and was raised by staunch Catholic parents; John Sagwe Obanyi and Theresa Kwamboka, both deceased.
He attended St. John's Minor Seminary at Rwakaro in Migori County, where he obtained his O-Level Certificate.
Later he obtained a Master's degree and a Doctorate, both in Canon Law, awarded by the Pontifical Lateran University in Rome, Italy.
In 2004, upon his return to Kenya from postgraduate studies in Rome, Father Joseph Obanyi Sagwe was appointed as the Vicar General of the Catholic Diocese of Kisii.
On 23 June 2018 Bishop Joseph Obanyi Sagwe was appointed Apostolic Administrator of the Catholic Diocese Bungoma, Kenya.