Gnaeus Cornelius Lentulus Marcellinus (c. 90 BC – c. 48 BC) was a Roman statesman and consul of 56 BC. He was married at least twice. His first wife is unknown but his second wife was probably Scribonia, at least twenty years his junior, who later became the second wife of Augustus.

By his first wife he was the father of Lentulus Marcellinus, Caesar's quaestor put in command of his fortifications at Dyrrhachium in 48 BC. By Scribonia he was father of two children, a boy and a girl.^[5] The boy was Cornelius Marcellinus.^[6] Some authorities, such as Ronald Syme, believed Cornelius Marcellinus died young;^[7] however, John Scheid has persuasively argued that he should be identified with Publius Cornelius Lentulus Marcellinus, consul of 18 BC.^[8]

The girl was Cornelia, who married Paullus Aemilius Lepidus (suffect consul in 34 BC), only to die the year her brother ascended to the consulate.^[9]

Marcellinus died before 47 BC. Scribonia remarried Augustus and became mother to his only child, Julia the Elder.