The Diocese of Niigata (Latin: Dioecesis Niigataënsis, Japanese: カトリック新潟教区 ) is a Latin Church diocese of the Catholic Church located in the city of Niigata in the ecclesiastical province of Tokyo in Japan.

[1] French botanist Father Urbain Faurie was one of the early missionaries to the Niigata area, who arrived in Japan in July 1873.

On April 16, 1962 the Prefecture was raised to a Diocese; the first bishop was John Shojiro Ito.

In 1984, the Grey Nuns of the Cross (Sisters of Charity of Ottawa) established the Élisabeth Bruyère Convent in the city of Yamagata, where they worked closely with the Missionaries of the Sacred Heart.

The sisters' apostolate includes parish ministry, teaching kindergarten, as well as, at the Maria Komakusa Day Care Center.