Onyango was a lay reader at
St Stephen's Cathedral in
Kisumu before being appointed as a deacon in 1984. In February 2018, she was appointed a
Canon in
Bondo Diocese. She is the chair of The Africa Centre for Biblical Equity, a
Langham scholar and a founder of the Circle of Concerned African Women Theologians.
Election as Bishop Onyango was appointed assistant bishop of Bondo during the
synod of the Diocese of Bondo,
Siaya County in January 2021. She is the first woman to hold the position of bishop in the ACK, after approval of a proposal to allow women to become bishops in 2013, the first female Anglican bishop in east and central Africa, and the fourth on the African continent. She will work with
David Kodiah in training clergy, as well as initiatives focused on ending
gender based violence and encouraging child empowerment. Speaking after her appointment, she said, "I am thankful to be asked to participate in a well-structured pastoral ministry focusing on marriage, family and gender issues, including empowerment of widows. I particularly expect us to offer hope for those shackled by gender-based violence." Her appointment was challenged by six lay members of the synod, who argued Bishop Kodia had cajoled the synod into affirming her appointment and that the diocese was unable to afford an assistant bishop. A 2014 informal agreement of
GAFCON put a
moratorium on the
ordination of women in certain provinces, however the Kenyan General Synod affirmed its support for women bishops in September 2019. ==Personal life==