Autonomist Union was a regionalist Italian political party active in Aosta Valley.
It was founded in 1987 by Roberto Gremmo as the local emanation of Piedmontese Union. In the 1988 regional election the party won 1.6% and Gremmo was elected to the Regional Council. In 1989-1991 Gremmo, who was as also leader of Piedmontese Union, refused to participate to the founding process of Lega Nord and, since then, the party begun its decline. For the 1992 general election, Gremmo merged the party into the Alpine League, which won 0.7% in the 1993 regional election, compared to the 7.6% of Lega Nord Valle d'Aosta.