424 is a year in the 5th century of the Gregorian calendar.

424 or 4-2-4 may also refer to: 424 BC, a year in the 5th century BC of the Gregorian calendar MÁV Class 424, a class of Hungarian steam locomotives Area code 424, California, United States 4-2-4 (locomotive), a steam locomotive configuration in Whyte notation 4-2-4 (association football), an association football (soccer) field formation