In countries with limited water resources that increasingly rely on imported food, sustainable fish farming offers a promising pathway to improve food security. This study focuses on Saudi Arabia, an arid country prioritizing domestic aquaculture expansion under its Vision 2030 initiative, and investigates consumer preferences for domestically farmed rainbow trout (Oncorhynchus mykiss) as a viable substitute for imported salmon. Using a discrete choice field experiment at point-of-sale with 333 consumers in Riyadh and Jeddah, we estimate willingness-to-pay (WTP) for key rainbow trout attributes, including origin, certification, product form, processing method, and color. Results show strong preferences for domestically produced, SAMAQ-certified (a national aquaculture quality label), fresh fillets with orange color, and significant WTP premiums for these traits. We also compare these WTP estimates with production cost scenarios to assess the economic feasibility of substituting imported salmon with domestically farmed rainbow trout. Findings suggest that, under efficient production scales, domestically produced trout can be cost-competitive with imports when aligned with consumer preferences. This study contributes new evidence from an arid, import-dependent country and highlights how aligning supply with consumer demand can support aquaculture expansion. The results offer practical guidance for food system transformation in similar contexts globally.