1704 (MDCCIV) was a leap year starting on Tuesday of the Gregorian calendar and a leap year starting on Saturday of the Julian calendar, the 1704th year of the Common Era (CE) and Anno Domini (AD) designations, the 704th year of the 2nd millennium, the 4th year of the 18th century, and the 5th year of the 1700s decade. As of the start of 1704, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1923.

In the Swedish calendar it was a leap year starting on Friday, one day ahead of the Julian and ten days behind the Gregorian calendar.