Polo Se'lab was a Bothan senator of the male persuasion. As a junior senator, he represented the Bothan sector within both the Galactic and Imperial Senates.
Prior to Palpatine's election as Supreme Chancellor, Se'lab cultivated a friendly relationship with Sayer Mon Neela. Leading up to the Clone Wars, he regularly chose to abstain from votes of political significance within the Senate. The senator advocated for Bothawui's neutrality during the Clone Wars, declining to involve it in any initial military conflicts.
During the era of the Galactic Empire, he threw his support behind the Alliance to Restore the Republic after his wife perished in an Imperial assault on a Bothan Spynet installation. He was then appointed commander of Alliance forces stationed on Carosi XII, where he encountered Neela once again.