Youghal
- The Wardenship of Youghal, in the Diocese of Cloyne, was founded by Thomas, Eighth Earl of Desmond.
- http://www.newadvent.org/cathen/15736a.htm

York, Use of
- Principle in medieval canon law that while as regards judicial matters, as regards the sacraments, and also the more solemn fasts, the custom of the Roman Church was to be adhered to.
- http://www.newadvent.org/cathen/15735a.htm

York, Ancient See of
- The seat of metropolitan jurisdiction for the northern province.
- http://www.newadvent.org/cathen/15733b.htm

Yellow Knives
- A sub-arctic Déné tribe, called the Copper Indians by Hearne and other early English writers, and Red Knives by Mackenzie and Franklin.
- http://www.newadvent.org/cathen/15733a.htm

Yazoo Indians
- A small tribe formerly living on the lower course of Yazoo River, Mississippi, in close connection with several other tribes, including the Tonica.
- http://www.newadvent.org/cathen/15732d.htm

Yaqui Indians
- A Cahita tribe, formerly dwelling near the Rio Yaqui.
- http://www.newadvent.org/cathen/15732c.htm

Yamasee Indians
- A Muskhogean tribe, mentioned frequently in the history of South Carolina, residing formerly near the Savannah River and in Florida.
- http://www.newadvent.org/cathen/15732b.htm

Yakima Indians
- A Shahaptian tribe formerly dwelling on the banks of the Columbia, the Wénatchee, and northern branches of the Yakima Rivers, in the east of Washington.
- http://www.newadvent.org/cathen/15732a.htm

Yuracaré Indians
- A Bolivian tribe living between Santa Cruz de la Sierra and Cochabamba.
- http://www.newadvent.org/cathen/15738c.htm

Yun-nan
- The Mission of Yun-nan includes the whole province, which is situated in the southwestern corner of China.
- http://www.newadvent.org/cathen/15738b.htm

Yukon, Prefecture Apostolic of
- Occupies the extreme northwestern portion of the Dominion of Canada.
- http://www.newadvent.org/cathen/15738a.htm

Yucatán, Archdiocese of
- Located in the Republic of Mexico; Campeche and Tabasco are its suffragans.
- http://www.newadvent.org/cathen/15737b.htm

Ysambert, Nicolas
- French theologian. (1565-1642)
- http://www.newadvent.org/cathen/15737a.htm

Young Men's Institute
- A Catholic fraternal organization, founded on 4 March, 1883, at San Francisco, California.
- http://www.newadvent.org/cathen/15736b.htm