Marcus Popilius Laenas was a Roman politician in the second century BC.
In 154 BC, Laenas was sent as an ambassador to Liguria to investigate the accusations of the residents of the allied city of Massalia against the Ligurians of depredations and raids.
[1] In 146 BC, as part of an embassy to Corinth, Laenas was beaten up by a seditious crowd.
This prompted Lucius Mummius to sack the city later that year in the Achaean War.
[3] There he unsuccessfully attempted to end the insurrection led by Viriathus, a Lusitanian chieftain that had defeated his consular predecessor.