Short answer — all non-residents over 16 and any resident aged between 16 and 65. If you’re trying to catch a fish in Florida, you’d better make sure you’re doing it legally. And watch out: even if you’re helping someone else fish by baiting their hooks and setting up their gear, you need a fishing license, too. There are some exceptions, though:

If you’re on a registered Florida fishing charter in saltwater, you don’t need to purchase your own license.
You don’t need a license to fish from a licensed pier.
Florida residents with severe disabilities can fish for free with a Florida Resident Disabled Person Hunting and Fishing License.
Military personnel from Florida can fish for free if they’re visiting home for up to a month.
Florida residents receiving benefits or food stamps, you can do land-based saltwater fishing without a license.
Any Florida resident can get a free shoreline fishing license, which allows you to fish for saltwater species from land or from structures attached to land.
Anyone who’s are eligible to fish without a license should make sure to bring proof that they are qualified to do so to show the Coast Guard. For instance, children under 16 should bring proof of age with them.

What if I’m a senior?
If you are age 65+ and are from out of state, you will still need a regular salt or freshwater fishing license. Senior Florida residents can fish for free but must bring proof of age and address. They can also get an optional and free Resident 65+ Hunt/Fish certificate.