Martin Luther King Jr. Day is a United States federal holiday marking the birth day of Rev. Dr. Martin Luther King Jr. It is observed on the third Monday of January each year, around the time of King's birthday, January 15. This year, the Martin Luther King Jr. Day of Service will be recognized on January 18, 2016. King was the chief spokesman for nonviolent activism in the civil rights movement, which successfully protested racial discrimination in federal and state law. He was assassinated on April 4, 1968 in Memphis, Tenn.