The Southwest Florida International Airport has one terminal divided into three concourses: Concourse B holding Boarding Gates B1-B9, Concourse C holding Boarding Gates C1-C9, and Concourse D with Boarding Gates D1-D10. The capacity of terminals is approximately 10 million passengers each year, with 28 Boarding Gates on three concourses (B, C, and D).

On Concourse B, the following Air Lines operate flights: Air Canada - Gate B3; Eurowings - Gate B1; Frontier uses Gates B5, B7, and B9; Southwest uses Gates B2, B4, B6, and B8; Sun Country - Gate B9.

On Concourse C, the following Air Lines manage flights: Delta - Gates C2, C4, C6, C9; WestJet - Gates C1, C7; United - Gates C1, C3, C5, C7 (Exception: some morning departures and arrivals in Concourse B).

On Concourse D the following Air Lines serve flights: American - Gates D1, D3, D5, D7, and D10; JetBlue - Gates D4, D6, D8; Spirit - Gates D2, D4, D7, D10;

The terminal buildings "Concourse A" and "Concourse E" have been currently reserved for a future project which aims to expand the terminals to 65 gates on five concourses (A-E). On the lower level of Concourse B, there are Customs and Immigration Services.