He finished a Jesuit school, and in his youth was a junior court official. Wybicki was elected a deputy to the Repnin Sejm, the session of Polish parliament in 1767, on the eve of the First Partition of Poland. Subsequently he joined the insurgency known as the Confederation of Bar (1768–1772), aimed at opposing the Russian influence and king Stanisław August Poniatowski. He was one of the advisors ("konsyliarz") of the Confederacy, acting as a diplomat. After the failure of the uprising, he spent some time in the Netherlands, studying law at Leiden University.