Animal Crossing: New Horizons is filled with different types of fish to catch. They spawn in different places, at different times of the year, and at different times a day. This will also vary depending on whether you are in the northern or southern hemisphere.
Below, you will find two tables, one for the northern hemisphere and one for the southern hemisphere, detailing fish types, spawns, times of the year, times of day, and the price that you can get for selling the fish.
The list is not complete, but we will be updating it daily as we catch more fish.
Nothern Hemisphere
Southern Hemisphere
Some if the information in the above tables was drawn from the Animal Crossing: New Horizons wiki.