St. Mary Cathedral Basilica, Gothic Revival cathedral in Galveston, United States.

St. Mary Cathedral Basilica is a Gothic Revival cathedral of pale stone facing a street in Galveston, Texas. Two square towers rise on the right, each behind a low parapet and topped by a pointed spire with a cross; the taller tower stands farther right. Between them the central section peaks in a gable, with a large pointed-arch window above a stepped-gable entrance with double doors. A figure stands atop the left tower.

Jean-Marie Odin dedicated a wooden St. Mary Church on February 6, 1842, built with help from Galveston founder Michel Branamour Menard and Dr. Nicholas Labadie. Its brick replacement was begun with 500,000 bricks shipped from Belgium as ballast and dedicated on November 26, 1848, the year after the Diocese of Galveston was erected. A cast-iron Mary, Star of the Sea statue was set on a transept tower in 1878, and the two front spires were raised to 80 feet in 1886.

St. Mary's is the mother church of Catholics in Texas and, since 2009, one of the worship sites of the merged Holy Family Parish. A cast-iron statue of Mary, Star of the Sea stands on the transept tower, and sailors once used the lit crown as a navigation aid when entering the Port of Galveston.

The cathedral faces Church Street between 20th and 21st Streets in downtown Galveston. Its main entrance is the dark double door beneath the large pointed-arch window; the two front spires rise 80 feet (24 m). The building reopened in 2014 after six years of repairs following flooding by Hurricane Ike, which put more than 5 feet (1.5 m) of water inside.

In 1878 a cast-iron statue of Mary, Star of the Sea was installed on the transept tower, and sailors reportedly used the lit crown as a navigation aid when entering the Port of Galveston. The statue was removed for restoration in 2019 and reinstalled in 2020.