The Jacksonville Sharks are a professional indoor football team based in Jacksonville, Florida, playing their home games at the Jacksonville Veterans Memorial Arena, known for sponsorship purposes as Sea Best Field. Beginning in 2017, the Sharks began play as charter members of the National Arena League (NAL). They were members of the Arena Football League (AFL) from 2010 to 2016 and won the championship of their division in the first four seasons of their existence.
The Sharks joined the AFL for the 2010 season, following the league's complete reorganization the previous year. In their inaugural season, they set the league record for most regular season wins by an expansion team, winning twelve of their sixteen games, and ranked third in the league in ticket sales and average attendance. They advanced to the 2010 AFL playoffs, claiming the South Division title. In their second year in the league, they advanced to the ArenaBowl XXIV, defeating the Arizona Rattlers 73–70, for the first AFL Championship in franchise history. The Sharks left the AFL after the 2016 season and joined the NAL.