The cathedral church of the diocese is Holy Trinity Cathedral, Wangaratta. The foundation stone was laid in 1908 by Bishop Arthur Green, the Bishop of Ballarat, and was dedicated on 24 August 1909. A second section was built between 1922 and 1924. The building was faced in locally quarried granite to a design by the Englisharchitect Walter Butler. The baptistery, designed by the church architect Louis Williams, was completed in 1965.
The cathedral bells, cast in 1806, are the oldest ring of eight in Australia. The current organ was built in 1902 by Henry Willis & Sons and is the fourth instrument to be housed in the cathedral.
The Rector of the Parish of the Holy Trinity, Wangaratta (the cathedral parish) is designated as Dean of Holy Trinity Cathedral. The current incumbent is Michael O'Brien.