1578 (MDLXXVIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.
|Centuries:||15th century – 16th century – 17th century|
|Decades:||1540s 1550s 1560s – 1570s – 1580s 1590s 1600s|
|Years:||1575 1576 1577 – 1578 – 1579 1580 1581|
- January 31 – Battle of Gemblours – Spanish forces under Don John of Austria and Alexander Farnese defeat the Dutch. Don John begins to recover control of the French-speaking Southern Netherlands
- August 4 – Battle of Al Kasr al Kebir – The Moroccans defeat the Portuguese. King Sebastian I of Portugal is defeated and killed in North Africa, leaving his elderly uncle, Cardinal Henry, as his heir. This initiates a succession crisis in Portugal.
- October 1 – Alexander Farnese, Prince of Parma, succeeds Don John as Spanish Governor-General of the Netherlands.
- Martin Frobisher held the first celebration of Thanksgiving by Europeans in North American at Newfoundland by the Frobisher Expedition.
- Tibet – Sonam Gyrso receives from prince Atlan Khan the title of "Talaï" and becomes the third Dalai Lama.
- Battle of Wenden – The Russians are defeated by the Swedes, who proceed to take Polotsk.
- The Ottoman Empire conquers Abkhazia.
- Sixth and so far the last outbreak of the sweating sickness in England