You find vendors for an event by looking where vendors already gather. Online vendor marketplaces, Facebook groups for local makers and food sellers, Instagram, and event platforms that list vendor opportunities are the usual starting points.
Word of mouth works too. Organizers who run recurring markets tend to build a roster over time, and vendors often refer other vendors. Visiting other markets in your area and talking to sellers in person is another common way to fill spots.
Vendor marketplaces like Marketlly let you search vendors by category and location, then contact them directly through the platform.
The right approach depends on the event. A craft fair needs makers, a food festival needs licensed food vendors, and a farmers market needs growers and producers. Knowing which type of vendor you want narrows down where to look.