The global market for seafood alternatives is witnessing an exponential growth. Nevertheless, the nutritional quality of such products is scarcely studied. Thus, this study aimed to evaluate, for the first time, the nutritional quality of seafood alternatives launched in the global market from 2002 to 2021 and to compare them with the conventional seafood products. Using the Mintel Global New Products Database, the nutritional information of seafood alternatives (i.e., tuna, shrimps, calamari, fish fingers, fish sticks, salmon, caviar, and fillet) was retrieved, and compared with conventional products. A total of 149 seafood alternatives were identified, of which 83 items had complete mandatory nutritional labeling. Conventional products (n = 973) were also collected, from which 130 products have a complete nutritional labeling. Results revealed that tuna, shrimps, caviar and fillet alternatives contained significantly less protein than conventional products, while calamari, fish fingers, fish sticks and salmon alternatives had similar amounts to their conventional counterparts. Salt content was significantly higher in tuna, fish fingers and sticks substitutes, but lower in shrimps, calamari and caviar alternatives compared to conventional products. Overall, the commercially available seafood alternatives have nutritional strengths and some shortcomings to be further addressed in future research such as low protein content. Additionally, fortification of seafood alternatives with micronutrients, such as omega-3 fatty acids and vitamins (A, B, and D), should be considered to ensure a nutritional equivalence with the conventional products.