Publius Sempronius Asellio (born around 158 BC, died after 91 BC) was an early Roman historian and one of the first writers of historiographic work in Latin. He was a military tribune of P. Scipio Aemilianus Africanus at the siege of Numantia in Hispania in 134 B.C. Later he joined the circle of writers centred around Scipio Aemilianus. Asellio wrote the history of the events of which he was engaged in, and thus preceded Caesar in his more famous accounts of his military campaigns.