The aircraft resulted from U.S. Department of Defense studies in 2018 to recapitalize the United States Air Force's (USAF) aging tactical aviation fleet.

The F-15EX is a variant of the F-15 Advanced Eagle, a further development of the F-15E design initially intended for export and incorporates improved internal structure, flight control system, and avionics.

[4] In the 2010s, the United States Air Force (USAF) was facing an incoming shortfall of its fighter fleet size in the 2020s due to deferred and downscaled modernization plans from budget cuts following the end of the Cold War in 1991, and the focus on asymmetric counterinsurgency warfare after the 11 September 2001 terrorist attacks.

[5] However, by the mid-2010s, the F-15C/D fleet was aging beyond the point of economic sustainability and would not be serviceable by the 2030s, while the F-35 program was facing delays, resulting in a requirement to recapitalize the fighter shortfall as the legacy F-15s retire by the mid-2020s.

[12] The F-15EX improvements included the AESA radar, IRST, and EPAWSS from the existing F-15 upgrade programs while combining the benefits of the F-15QA such as the revised structure with a service life of 20,000 hours, new cockpit and flight controls, and the proposed AMBER (Advanced Missile and Bomb Ejector Rack) system to enable the carriage of up to 22 air-to-air missiles.

[22] The Air Force's proposed budget for fiscal 2024 includes funds to buy 24 more F-15EXs,[23] which would bring the planned fleet up to 104 aircraft.

The Advanced Eagle consolidated several upgrades to the F-15E developed for export customers, including full integration of the General Electric F110-GE-129 and the AN/ALQ-239 Digital Electronic Warfare System (DEWS) that replaced the legacy TEWS, and introduced a revised wing structure for increased service life, an enhanced cockpit originally proposed for the F-15SE Silent Eagle and digital fly-by-wire control system that replaced the original hybrid electronic/mechanical system and enables the activation of two additional wing pylons;[24] the fly-by-wire eliminated flutter modes causing stability issues that resulted in the two outboard wing pylons being deactivated in earlier F-15 variants.

[25] Starting from the F-15QA for the Qatari Emiri Air Force, the Advanced Eagle introduced a further revised wing structure that increased service life to 20,000 hours, the new Advanced Display Core Processor II (ADCP II) mission computer, and a new cockpit with a 10 in × 19 in (25 cm × 48 cm) large area display (LAD) each for the pilot and weapon systems officer (WSO).

Using proposed expanded racks and CFT weapons stations, it can potentially carry sixteen AIM-120; four AIM-9; and two AGM-88 HARMs, although this has not been tested or funded.

For precision strike, it can carry sixteen GBU-39 Small Diameter Bombs; four AMRAAMs; one 2,000 lb Joint Direct Attack Munition; two HARMs; and two fuel drop tanks.

While the Advanced Eagle's strengthened structure makes it heavier than earlier F-15 variants, the digital fly-by-wire control system and the increased dynamic thrust envelope of the F110-129 engines provide it with substantially improved maneuverability and handling characteristics over legacy F-15s and enables the pilot to maneuver aggressively with no angle-of-attack limits.

The F-15EX's APG-82(V)1 radar, initially designated APG-63(V)4, combines the AESA antenna of the APG-63(V)3 with the processor of the APG-79(V) found on the F/A-18E/F Super Hornet as well as a new cooling system and Radio Frequency Tunable Filters (RFTF) to enable simultaneous radar and electronic warfare functions while integrated with the AN/ALQ-250 EPAWSS electronic warfare suite.

[38] On 5 June 2024, Oregon's 142nd Wing received its first F-15EX with the fighter landing at Portland Air National Guard Base, while the second arrived a month later.

[42][43][44] In addition to the 84 F-15SA purchased in 2011, Boeing discussed the sale of 54 F-15EXs to Saudi Arabia during the 2024 World Defense Show in Riyadh.

[48] As of 21 November 2022, Indonesia's planned purchase of F-15s is in advanced stages and awaiting final sign-off from the government, as stated by the Indonesian Minister of Defense.

Speaking after meeting his U.S. counterpart Lloyd Austin in Jakarta, Prabowo Subianto said that Boeing had agreed to the financial offer proposed and he is confident the package is affordable.