To identify a suitable substrate to enhance sustainable access to affordable quality feed protein in Uganda, growth performance and nutritional composition of housefly larvae grown on three common substrates; cow dung (CD) chicken manure (CM) and brewery waste (BW) for 5 days was determined. Eighteen bags were randomly filled with one kilogram (1000g) of each of the three substrate in six replicates were allowed to attract adult housefly that deposited eggs whose larvae were harvested on the 3 rd , 4 th, and 5th day. The weight of larvae was 43.72 for CM, 39.65 for BW and 33.91 for CD. The crude protein ranged from 45.38-44.21 for CD, 48.60-53.0 for CM and 46.24-50, 32 for BW and significantly differed among substrates (p<0.05) with the highest recorded in chicken manure (CM). On the other hand, the crude protein was significantly high in larvae nourished with Chicken manure (CM) and lowest in cow dung (CD) crude fat did not significantly differ. Results from the study indicated that culturing housefly larvae on chicken manure for 3 days post egg laying offers higher biomass and nutritional quality protein than using cow dung and brewery waste.