Show ContentsDease History, Family Crest & Coats of Arms

The Irish name Dease is an Anglicized version of the Gaelic name Déiseach, which is thought to have originally been a nickname for a member of the vassal community (feudal servants) called the Déis, a word of uncertain origin. There was also a Decies barony in County Waterford, and in some cases, this name likely originated with a native of that barony.

Early Origins of the Dease family

The surname Dease was first found in counties Cork and Mayo (Irish: Maigh Eo) located on the West coast of the Republic of Ireland in the province of Connacht. It is thought that immigrants from Waterford took on this name after they arrived in their new homelands.

The first recorded instance of the name appears to be a bearer of Dacy, who was a Drogheda juror in Cork as early as 1313. There is a legend in Cork that all the Deasys of the county are ancestors of a child who was rescued from a massacre in the barony of Decies in about 1620. It is claimed that he was then protected by the O'Donovans of the Island, and went on to have seven sons.

Early History of the Dease family

This web page shows only a small excerpt of our Dease research. Another 43 words (3 lines of text) covering the years 1568, 1622, 1652, 1659, 1750, 1774, 1793, 1798, 1812, 1819 and 1883 are included under the topic Early Dease History in all our PDF Extended History products and printed products wherever possible.

Dease Spelling Variations

Spelling variations of this family name include: Deasy, Deacy, Dacy, Dacey, Dease, Daase, Dece and others.

Early Notables of the Dease family

Notable amongst the family name at this time was

  • Thomas Dease (1568-1652), Bishop of Meath in 1622, and a poet
  • William Daase (c.1750-1798), a noted surgeon and medical writer, as was his son Richard Dease (1774-1819). Rickard Deasy (1812-1883) was a Lord Justice of Appeal in County Cork


United States Dease migration to the United States +

Some of the first settlers of this family name were:

Dease Settlers in United States in the 19th Century
  • Dennis Dease, who settled in Philadelphia, Pennsylvania in 1855
  • Dennis Dease, who settled in America in 1863
Dease Settlers in United States in the 20th Century
  • Warren Dease, aged 7, who arrived in Honolulu, Hawaii, in 1914
  • Robert Dease, aged 20, who arrived in America, in 1918
  • Thomas Dease, aged 20, who arrived in America, in 1918
  • Alex Dease, aged 18, who arrived in America, in 1921
  • Alexander Dease, aged 18, who arrived in America, in 1921

Canada Dease migration to Canada +

Some of the first settlers of this family name were:

Dease Settlers in Canada in the 18th Century
  • Mr. John Dease U.E. (b. 1741) born in Ireland who settled in Montreal, Canada East, Quebec c. 1786 he joined was known as a Medical Doctor, Captain and Superintendent of the Indian Department, he joined the North West Company [Hudson's Bay Company] and became Factor, he became Chief Factor at Fort Spokan and died in 1827, he married Jane French having 7 children [1]

Australia Dease migration to Australia +

Emigration to Australia followed the First Fleets of convicts, tradespeople and early settlers. Early immigrants include:

Dease Settlers in Australia in the 19th Century
  • J. Dease, who arrived in Adelaide, Australia aboard the ship "Orleana" in 1839 [2]

Contemporary Notables of the name Dease (post 1700) +

  • The Rev. Dennis Dease (1991-2013), American academic and Roman Catholic priest, 14th President of the University of St. Thomas in Minnesota
  • Michael Dease (b. 1982), American jazz trombonist, composer and producer
  • William Dease (1752-1798), Irish surgeon and anatomist
  • Teresa Ellen Dease (1820-1889), Irish-born, Canadian Roman Catholic nun and the foundress of the Loreto Sisters
  • Conly John Paget Dease (1906-1979), Australian radio presenter and quiz show host in the 1940s and 1950s
  • Maurice James Dease VC (1889-1914), British Army officer during the First World War, recipient of the Victoria Cross
  • Peter Warren Dease (1788-1863), Canadian fur trader and arctic explorer, member of Sir John Franklin's second expedition to the Arctic


  1. Rubincam, Milton. The Old United Empire Loyalists List. Genealogical Publishing Co., Inc, 1976. (Originally published as; United Empire Loyalists. The Centennial of the Settlement of Upper Canada. Rose Publishing Company, 1885.) ISBN 0-8063-0331-X
  2. State Records of South Australia. (Retrieved 2010, November 5) ORLEANA 1839. Retrieved from http://www.slsa.sa.gov.au/BSA/1839Orleana.htm


Houseofnames.com on Facebook