The Diet of Speyer or the Diet of Spires (sometimes referred to as Speyer V) was an Imperial Diet of the Holy Roman Empire which took place in 1570 in the Imperial City of Speyer (also known as Spires, in present-day Germany). The diet condemned the results of the Diet of Speyer of 1526 and attempted to forbid any further Reformation. It resulted in the Protestation at Speyer.