Martin Luther King Jr. Day (MLK Day) is observed on the third Monday in January each year in the United States.

Key dates

  • Martin Luther King Jr.’s actual birthday is January 15.
  • Because the holiday is fixed to the third Monday in January, it always falls between January 15 and January 21.

Why that date?

  • The day is a federal holiday created to honor King’s birthday and his role as a leader of the U.S. civil rights movement.
  • The “third Monday” rule follows the same pattern as other U.S. Monday holidays to create a long weekend while staying close to January 15.

TL;DR: MLK Day = third Monday of January; King’s birthday = January 15.