西圣安东尼奥（San Antonio Oeste），阿根廷内格罗河省的一个港口城市，是圣安东尼奥区的首府。西圣安东尼奥东临东圣安东尼奥，西邻格鲁塔斯。

San Antonio Oeste is a port city in the Argentine province of Río Negro, and head of the department of San Antonio.

The town is bordered by its sister communities of San Antonio Este, to the east, and Las Grutas, to the southwest. Discovered by an expedition of the Spanish Empire in 1779, San Matías Gulf became the site of an outpost, San Antonio (so named in honor of St. Anthony of Padua). Water scarcity led the original settlement to fail in 1905, leading the community to settle west of the gulf, in what today is San Antonio Oeste.