On 28 August 2019, he was elected to serve as the ninth Archbishop of Uganda and Bishop of Kampala, effective 1 March 2020.
[3] Mugalu was born on 15 August 1962, to Jessica Nanyonjo and Besweri Kaddu, at Gulama-Najja Village, Kyaggwe County, in present-day Buikwe District.
He was confirmed by Bishop Misaeri Kawuma, on 22 September 1979, at Namataba, Kyaggwe County, in present-day Mukono District.
[6] In 2023, Kaziimba expressed support for the Ugandan Anti-Homosexuality Act, which introduces the death penalty for certain convictions of homosexuals.
Kaziimba disputed criticism of his stance by the Archbishop of Canterbury, Justin Welby, noting that laws criminalising homosexual acts had first been introduced to Uganda by the British in colonial times.