The 1520s was a decade that started on 1 January 1520 and ended on 31 December 1529.

It is distinct from the decade known as the 153th decade which began on January 1, 1521 and ended on December 31, 1530.

• Aztecs surrender to the Spanish conquistadors.
• Ferdinand Magellan takes a trip around the world, and discovers the Philippines and Guam.
• Martin Luther and the Protestant Reformation

• Anne Askew, English Protestant martyr (1521)
• Taqi al-Din, Muslim scientist (1526)

• Ferdinand Magellan, Spanish explorer (1521)
• Zhengde, Emperor of China (1521)
• Wijerd Jelckama, Frisian warlord and rebel (b. 1490)
• Marko Marulic, Croatian poet (1524)
• Vasco da Gama, Portuguese explorer (1524)
• Niccolò Machiavelli, Italian writer and statesman.