León María Guerrero y Leogardo (January 21, 1853 – April 13, 1935) was a Filipino writer, revolutionary leader, politician, the first licensed pharmacist in the Philippines, and one of the most eminent botanists in the country in his time. Guerrero was appointed head of the military pharmacy in Zamboanga City and at the marine hospital in Kawit, Cavite. Later, he would manage the popular Binondo Pharmacy in Manila. His scientific curiosity led him to study the therapeutic uses of Philippine plants, from which he extracted pharmacological ingredients.