Uff da! (sometimes also spelled huffda, uff-da, uffda, uff-dah, ufda, ufdah, or uf daa) is an exclamation or interjection expressing bafflement, surprise, or dismay. Of Norwegian origin, the phrase was brought by Scandinavian Americans in the Upper Midwest, New England, and Pacific Northwest regions of the United States during the 19th century. The Swedish exclamation ojdå is similar in meaning and usage.  
In Norwegian, uff or huff is an interjection used when something is unpleasant, uncomfortable, hurtful, annoying, sad, or irritating. Uff da is most often used as a response when hearing something lamentable (but not too serious), and could often be translated as "Oh, I'm sorry to hear that".
North American usage
Uff da can be used as an expression of surprise, astonishment, exhaustion, relief and sometimes dismay. Within Scandinavian-American culture, Uff da frequently translates to: "I am overwhelmed", somewhat similar to the Yiddish phrase oy vey. Uff da can often be used as an alternative for many common obscenities. 
The phrase has become a marker of Scandinavian heritage. As a result, the term is predominantly prevalent in the Upper Midwest, United States––a region with large populations of people with Scandinavian roots––and has been applied to names of places and events, such as:
- Uff-Da Airport, located in Stoughton, Wisconsin.
- Uffda Fest!, an annual event held in Spring Grove, Minnesota.
- Uff Da Days, an annual event held in Ostrander, Minnesota.
- Uffda Day Fall Festival, an annual event held in Rutland, North Dakota.
- Culture of Minnesota
- Culture of the Upper Peninsula of Michigan
- Culture of Wisconsin
- List of English words of Norwegian origin
- "Uff Da defined". Sons of Norway Blog. March 25, 2010. Retrieved March 1, 2019.
- Anette Broteng Christiansen (April 18, 2012). "'Uff da!' – A Piece of Norway in the U.S." Thor News. Retrieved March 1, 2019.
- "ojdå". Wiktionary. Retrieved March 1, 2019.
- "Søk i Bokmåls- og Nynorskordboka". Retrieved 2009-09-19.
- Haugen, Einar (1985). Norwegian English dictionary : a pronouncing and translating dictionary of modern Norwegian [Bokmål and Nynorsk], with a historical and grammatical introduction. University of Wisconsin. ISBN 0-299-03874-2
- Rob Lein. "Vikings bumble in draft? Uff da". Bismarck Tribune. Retrieved 2009-09-19.
- "Uff-Da Airport". airnav.com. 28 February 2019. Retrieved March 1, 2019.
- "UffDa Fest!". Spring Grove Lions Club. Retrieved March 1, 2019.
- "Uff Da Days". Ostrander, MN. Retrieved March 1, 2019.
- "Uffda Day". rutlandnd.com. Retrieved March 1, 2019.
- Martin, Jonathan, "Court Battle Shifts the Political Terrain for Senators in the Heartland", New York Times, October 7, 2018. Retrieved 2018-10-08.
- Allen, Harold B. (1973). The Linguistic Atlas of the Upper Midwest, Volume 1, (Minneapolis: University of Minnesota Press), ISBN 978-0816606863. OCLC 658192.
- Haugen, Einar (1957) Beginning Norwegian: a grammar and reader (George G.Harrap & Co Ltd) ISBN 978-0245531378
- Lovoll, Odd S. (1998) The Promise Fulfilled: A Portrait of Norwegian Americans Today (Minneapolis: University of Minnesota Press) ISBN 9780816628322
- Mohr, Howard (1987) How to talk Minnesotan : a visitor's guide (New York, NY: Penguin Books) ISBN 978-0143122692
- Stangland, E. C. (1987). Red Strangland's Norwegian Home Companion. (Dorset Press). ISBN 978-0880295215.
- Stangland, E. C. (1988). Uff Da Jokes. (Norse Press). ISBN 978-0960269242.
- Clark, Jayne (July 25, 2002). "True blue North? You betcha!". USA Today.