1518 (MDXVIII) was a common year starting on Friday of the Julian calendar, the 1518th year of the Common Era (CE) and Anno Domini (AD) designations, the 518th year of the 2nd millennium, the 18th year of the 16th century, and the 9th year of the 1510s decade. As of the start of 1518, the Gregorian calendar was 10 days ahead of the Julian calendar, which was the dominant calendar of the time.

• A plague of tropical fire ants devastates crops on Hispaniola.