The opposition politician, Salaamu Musumba has beaten NRM's Thomas Kategere and six others to the Kamuli LC5 seat.
FDC eastern Vice President trounced her rivals with 49,356 votes overall which translated into a 67.6% share of the entire vote while Kategere returned with 21, 239 votes (29.1%).
Musumba was declared winner of the by-election on Friday morning by the Kamuli returning officer, Samuel Kiyingi in presence of Electoral Commission chairman, Badru Kigundu.
The other six who were independent polled as follows: Ibrahim Mbadhi 1,077 (1.5%), Kaloli Dhizaala 437 (0.6%), Charles Isanga 210 (0.3%), Fred Kamaniro 87 (0.1%), Michael Kifubangabo 346 (0.5%).
All votes from the 331 polling stations were received, said Kiyingi, who commended the security officials for a job well-done during the entire election process.
Electoral Commission boss Badru Kigundu urged those who had contested for the seat to work together with Musumba because they "also have good ideas".
New FDC President Maj. Gen Mugisha Muntu and other FDC big shots in the East were seen monitoring polling stations and Police managed to arrest 12 people in relation to violence.
The seat fell vacant in 2011 when court nullified the election of Kawugu Kawooya over lack of academic qualifications.