St George's Channel (Welsh: Sianel San Siôr, Irish: Muir Bhreatan) is a sea channel connecting the Irish Sea to the north and the Celtic Sea to the southwest.

Historically, the name "St Georges Channel" was used interchangeably with "Irish Sea" or "Irish Channel" to encompass all the waters between Ireland to the west and Great Britain to the east. Later^[when?] it was restricted to the portion separating Wales from Leinster, sometimes extending south to the waters between the West Country of England and East Munster; the latter have since the 1970s come to be called the Celtic Sea. In Ireland "St George's Channel" is now usually taken to refer only to the narrowest part of the channel, between Carnsore Point in Wexford and St David's Head in Pembrokeshire. However, it remains common in Ireland to talk about a cross-channel trip, cross-channel soccer, etc., where "cross-channel" means "to/from Great Britain".

The International Hydrographic Organization's publication Limits of Oceans and Seas defines the southern limit of "Irish Sea and St. George's Channel" as "A line joining St. David's Head (51°54′N 5°19′W / 51.9°N 5.317°W / 51.9; -5.317) to Carnsore Point (52°10′N 6°22′W / 52.167°N 6.367°W / 52.167; -6.367)"; it does not define the two waterbodies separately.

Saint George was a Christian martyr who lived in the 2nd and 3rd centuries AD.

Saint George or Saint George's may also refer to:

Saint George (c. 275/281 – 23 April 303) was, according to tradition, a Roman soldier from Syria Palaestina and a soldier in the Guard of Diocletian, who is venerated as a Christian martyr. In hagiography Saint George is one of the most venerated saints in the Catholic (Western and Eastern Rites), Anglican, Eastern Orthodox, and the Oriental Orthodox churches. He is immortalized in the tale of Saint George and the Dragon and is one of the Fourteen Holy Helpers. His memorial is celebrated on 23 April, and he is regarded as one of the most prominent military saints.

Many Patronages of Saint George exist around the world, including: Georgia, England, Egypt, Bulgaria, Aragon, Catalonia, Romania, Ethiopia, Greece, India, Iraq, Lithuania, Palestine, Portugal, Serbia, Ukraine and Russia, as well as the cities of Genoa, Amersfoort, Beirut, Botoşani, Drobeta Turnu-Severin, Timişoara, Fakiha, Bteghrine, Cáceres, Ferrara, Freiburg, Kragujevac, Kumanovo, Ljubljana, Pérouges, Pomorie, Preston, Qormi, Rio de Janeiro, Lod, Lviv, Barcelona, Moscow, Tamworth and the Maltese island of Gozo, as well as of the Scout Movement and a wide range of professions, organizations and disease sufferers.