There are plenty of ways to add a bit of heft to your Warrior of Light's coin purse in Final Fantasy XIV, like selling crafted and gathered items or passively earning money through Duty Roulettes. While many crafts sold on the market board use materials directly gathered by Botanists and Miners, Fisher often gets overlooked as a source of income.
Earning a large amount of gil can be an intensive process, even monotonous when gathering a large number of materials to sell. However, choosing a method you enjoy can make the time spent all the easier. Fans of fishing have a few options when looking to add a bit of gil to their stockpile.
How to earn gil as a Fisher in FFXIV
As with most methods of earning a healthy sum of gil in Final Fantasy XIV, most of your earnings as a Fisher will come from the market board. However, that doesn't mean that dumping your bag full of fish onto the market board will yield the results you were looking for. The price for certain fish can fluctuate based on several criteria. Sometimes, the most profitable item a Fisher can sell isn't even the fish itself, but what's inside.
Levequest Turn-ins and Grand Company Provisioning Missions
For crafters and gatherers, Levequests offer a large chunk of experience while also providing a small reward of gil. Disciples of the Hand have the benefit of crafting the turn-ins in large batches, meaning they can accept and complete the Levequest repeatedly to earn a profit. With the time required to catch the required materials, the same method isn't the most profitable use of your time as a Fisher.
Instead, your focus when earning gil as a Fisher doesn't need to be completing the Levequest itself but instead collecting and selling its turn-in requirement. Players looking to level their Crafters and Gatherers quickly rely on systems like the Firmament or Levequests and will buy the required materials off the market board to save time. Plenty of gil can be made from hasty Warriors of Light by gathering turn-in requirements for the current expansion's Levequests and selling the exact quantity required to complete them.
The same method applies for Grand Company Provisioning Missions, which update every 24 hours. These missions offer massive amounts of experience, and players will happily pay gil to earn it quickly if it means they don't have to wait and catch the fish themselves. The "catch of the day" is different with each reset, so pay attention to the Grand Company's timers and turn-in requirements.

Aetherial Reduction
Several endgame crafting recipes require one of the many versions of a material known as aethersand, making the newest variation of the material a fairly valuable item. By gathering collectables, a Disciple of the Land can use the Aetherial Reduction ability to break the collectable down, with a particular aethersand as a possible reward if the item's collectability meets a certain threshold. While aethersand could always be purchased using Crafters' scrips, gathering jobs can earn more of it quickly when the required collectable's node is available. Thanks to the addition of spearfishing, Fishers can gather a sizeable amount of aethersand from collectables, though certain fish like the Nosceasaur require the effect of Fisher's Intuition to be active.
Selling Fish for Recipes
The Fisher and Culinarian jobs go hand-in-hand in FFXIV, as many of Culinarian's seafood recipes require materials gathered directly by a Fisher. By referencing the Culinarian crafting log for any fish required throughout the various recipes, you can prioritize and sell which ones need to be caught for Culinarians to quickly purchase from the market board. However, this method doesn't result in the quickest sales unless a food item is currently the best for a particular class, but there's always the chance of your prized catch being sold if a player runs to the market board in search of any fish to complete their Culinarian crafting log.