1743 (MDCCXLIII) was a common year starting on Tuesday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1743rd year of the Common Era (CE) and Anno Domini (AD) designations, the 743rd year of the 2nd millennium, the 43rd year of the 18th century, and the 4th year of the 1740s decade. As of the start of 1743, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1923.