Floribert Bwana Chui Bin Kositi was honoured at a special Mass attended by hundreds of faithful at Saint Joseph Cathedral, where his body was moved from a public cemetery.
He was kidnapped and murdered in 2007 after blocking the transport of rancid rice from Rwanda.
Pope Francis recognised him as a martyr last year, and the Vatican formally beatified him in Rome.
Hundreds attended Tuesday’s Mass, many wearing shirts with his image and waving flags that called him a “martyr of honesty.”