The full answer
Sushi can be Halal depending on the ingredients.
Fish and rice may be permissible, but some sushi contains imitation seafood, sauces, mirin, cooking alcohol or other ingredients that require checking.
Always consider the complete dish rather than only the fish.
Answers in the Halal Knowledge Center reflect the standards followed by Halal Monitoring Services (HMS), which operates as part of the Shariah Board of America. HMS certifies only what it checks.