1664 (MDCLXIV) was a leap yearstarting on Tuesday of the Gregorian calendarand a leap year starting on Friday of the Julian calendar, the 1664th year of the Common Era (CE) and Anno Domini (AD) designations, the 664th year of the 2ndmillennium, the 64th year of the 17thcentury, and the 5th year of the 1660s decade. As of the start of 1664, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.

• March 12 – New Jersey becomes a colony of Britain.