High cost and scarcity of feed ingredients have continued to challenge the aquaculture. This present study assessed the potential of black soldier fly (BSF, Hermetia illucens L.) larvae meal (BSFLM) as a sustainable alternative source of animal protein in the diet of African catfish (Clarias gariepinus), a species widely farmed in Cameroon for its breeding potential and economic. Five diet formulations: a control diet with 100% fishmeal (FM, BSFLM0), and diets where FM was substituted at 50% (BSFLM50), 75% (BSFLM75), and 100% (BSFLM100) levels, were compared. Larvae of BSF were processed using three different methods: toasting, sand toasting, and boiling. Parameters assessed included the chemical and microbial properties of BSF larvae, catfish growth performance, health, consumer acceptance and economic viability of substituting FM with BSFLM. Our results demonstrate that boiling larvae significantly increased the dry and organic matter contents but reduced crude protein (CP) and fat levels, whereas toasting increased CP. Mineral content varied across processing methods: sand toasting had the highest calcium, boiling the highest iron, and toasting the highest potassium, sodium, and phosphorus levels. Sand-toasted larvae had the highest Escherichia coli levels, Lactobacillus was present only in boiled larvae, and there were no Enterobacteria or Salmonellain toasted or sand-toasted samples. At higher levels (75-100%), BSFLM improved catfish growth rates, feed conversion ratio, and survival compared to the control. Replacing FM with BSFLM also reduced production costs, increased profitability, and enhanced sustainability, as indicated by a lower fish-in-fish-out ratio. Inclusion of BSFLM significantly enhances the sustainability potential of aquaculture practices by reducing reliance on wild-caught fish for feed. Overall, BSFLM is a suitable alternative protein source that can support economic viability and environmental sustainability of aquaculture, promoting resilient fish farming practices.