He was the son of Lucius Sempronius Atratinus, consul in 444 BC and one of the first censors of the Republic.
[2] In 428 or 427 BC Sempronius held the consulship together with Lucius Quinctius Cincinnatus.
This consulship is dubious as it is only mentioned by Diodorus Siculus and is placed in-between the consuls of 428, Aulus Cornelius Cossus and Titus Quinctius Poenus Cincinnatus, and the consuls of 427 BC, Gaius Servilius Structus Ahala and Lucius Papirius Mugillanus.
His colleagues were Marcus Papirius Mugillanus, Quintus Fabius Vibulanus and Spurius Nautius Rutilus.
The only known event during the year was the proposal of an agrarian law by two of the Tribunes of the Plebs, which was vetoed by their own colleagues.