Systems, apparatus, articles of manufacture, and methods for leak detection and mitigation for hydrogen fueled aircraft are disclosed. An example apparatus disclosed herein includes programmable circuitry to predict, based on an engine condition of an aircraft, a pressure and a temperature for a location within an undercowl of an engine of the aircraft, determine, using a first stored parameter relationship, a lower detonation limit of hydrogen at the location based on the temperature and the pressure, determine, using a second stored parameter relationship, a lower flammability limit of hydrogen at the location based on the temperature and the pressure, and conduct a mitigation action in a hydrogen fuel distribution system based on a predicted hydrogen concentration at the location at least one of (a) exceeding the lower detonation limit or (b) exceeding the lower flammability limit.