Pietro Alessandro Gaspare Scarlatti (2 May 1660 – 22 October 1725) was an Italian Baroque composer, known especially for his operas and chamber cantatas. He is considered the most important representative of the Neapolitan school of opera.

Nicknamed by his contemporaries "the Italian Orpheus", he divided his career between Naples and Rome, where he received his training; a significant part of his works was composed for the papal city. He is often considered the founder of the Neapolitan school, although he has only been its most illustrious representative: his contribution, his originality and his influence were essential, as well as lasting, both in Italy and in Europe.

Particularly known for his operas, he brought the Italian dramatic tradition to its maximum development, begun by Monteverdi at the beginning of 17th century and continued by Cesti, Cavalli, Carissimi, Legrenzi and Stradella, designing the final form of the Da capo aria, imitated throughout Europe. He was also the inventor of the Italian overture in three movements (which was of the highest importance in the development of the symphony), of the four-part sonata (progenitor of the modern string quartet), and of the technique of motivic development. He was a model for the musical theater of his time, as evoked by Händel's Italian works, deeply influenced by his theatrical music. Eclectic, Scarlatti also worked on all the other common genres of his time, from the sonata to the concerto grosso, from the motet to the mass, from the oratorio to the cantata, the latter being a genere in which he was an undisputed master.

He was the father of two other composers, Domenico Scarlatti and Pietro Filippo Scarlatti.