The Cathedral of Saint Mary of the Immaculate Conception is the cathedral of the Roman Catholic Diocese of Lafayette in Indiana. It is located at 1207 Columbia Street in Lafayette, Indiana.
The congregation began in 1843 when a small group of Irish Catholic families in the area met for Mass in rented space. By the following year, they raised enough money to construct their own building. The brick Church of Sts. Mary and Martha stood at the intersection of Fifth and Brown Streets and was completed in 1846. In 1850, a school was constructed on adjacent land which came under administration of the Oblate Sisters of Providence in 1858.
In 1860, parishioner Lawrence Stockton donated a plot of land on Columbia Street to pastor Reverend Edmund Kilroy for construction of a church, rectory and school. Preliminary work began shortly thereafter, but stopped when the Civil War began in April 1861.
Reverend George Hamilton replaced Fr. Kilroy as pastor and oversaw completion of construction. The Gothic-style church was dedicated August 15, 1866.
In 1944, the Diocese of Lafayette-in-Indiana was created by dividing the Diocese of Fort Wayne and St. Mary's Church was chosen as cathedral for the new diocese. The Cathedral has undergone a number of changes including an interior redecoration and addition of a social hall in 2001.