In 2026, Southwest Airlines remains the undisputed king of the Boeing 737-700, operating a massive fleet of several hundred of this specific variant. Although Southwest is aggressively transitioning to the newer, more fuel-efficient 737 MAX 7 and MAX 8 models, the -700 continues to be the workhorse of their short-to-medium-haul network. This single-aisle aircraft is perfectly suited for Southwest's "point-to-point" business model and its ability to operate out of smaller, secondary airports. Other significant operators of the 737-700 include United Airlines and various low-cost carriers in Latin America, but none come close to the sheer volume held by Southwest. The -700 is prized for its reliability and "commonality," allowing Southwest to use the same pilots and maintenance crews across its entire all-737 fleet. As of early 2026, the airline continues to retire these older NGs (Next Generation) in favor of the MAX, but you will still find the -700 on a huge percentage of their daily flight schedule.