Walter Major was a family of Czechoslovak aircraft inline engines developed by Walter Aircraft Engines in the 1930s.
Available in either four or six cylinder configuration, with identical bore and stroke of and , respectively, the Walter Majors were primarily used in light aircraft. License-built in Poland by the state-owned Paà Âstwowe Zakà Âady Inà ¼ynieryjne (as the PZInà ¼. Major 4), the engine was used in, among others, Zlin Z-XIII, RWD-11 and one of the PWS-35 Ogar prototypes.