Is it possible for a goldfish to live in a 1-gallon tank?

No, it is not recommended for a goldfish to live in a 1-gallon tank as they require more space to thrive and stay healthy. Goldfish produce a lot of waste and need a larger tank with proper filtration to maintain good water quality. A larger tank, ideally 20 gallons or more, is recommended for a goldfish to live comfortably.