The Siege of Bad Kreuznach or the Spanish capture of Bad Kreuznach took place on 9 September 1620, in Kreuznach, Electorate of the Palatinate, between the Spanish forces of Don Ambrosio Spinola, commanded by Don Carlos Coloma de Saa, 1st Marquess of Espinar against the forces of the Electoral Palatinate during the Palatinate campaign, in the context of the Thirty Years' War. The Spanish troops stormed the city and obtained the surrender of the garrison. Later the town was released on a promise not to fight back against the Holy Roman Empire.