A customer's Shamrock Shake sitting on a table at McDonald's
|Country||United States, Canada, Ireland|
The Shamrock Shake was first introduced in 1970. Rogers Merchandising in Chicago created the shake. Initially, the shake was lemon/lime flavored with vanilla ice cream, lemon/lime sherbet, and vanilla syrup. By 1973, the shake was merely a green colored vanilla shake, eliminating the lemon/lime sherbet. It is now mint flavored. 
During the 1980s, McDonald’s used the Uncle O'Grimacey character to market Shamrock Shakes, which was a green version of Grimace who came to visit in March. McDonald's has since phased out that character from their mascot lineup.
In 1980, McDonald's introduced the Shamrock Sundae which consisted of vanilla ice cream topped with a mint green Shamrock syrup. The product was discontinued after one year due to poor sales.
In 2017 McDonald's introduced a few variants of the Shamrock Shake including the Shamrock Chocolate Shake, the Shamrock Chocolate Chip Frappé, the Shamrock Mocha, and the Shamrock Hot Chocolate.
In popular culture
- In The Simpsons episode "Stop or My Dog Will Shoot", Chief Wiggum and Lou debate whether the Shamrock Shake is just a vanilla shake dyed green, or if it is actually mint-flavored. Lou insists the chief only thinks he tastes the mint because the shake is green.
- In a Family Guy episode where Stewie abducts the entire cast of Star Trek: The Next Generation, he takes them to McDonald's. Jonathan Frakes requests a Shamrock Shake, to which Stewie replies that they have been discontinued as it is September.
- In This Is Us season 2 episode 9 ("Number Two"), Toby makes a healthy shake which he compares to a shamrock shake.
- In the American Dad! episode "The Life and Times of Stan Smith", Stan discovers that in heaven (after confusing it for Ireland), Shamrock shakes are available every third Friday of December.
- Huguenin, Patrick (2007-03-16). "Shamrock Shake Shocker: It's Disappeared!". The New York Daily News. p. 46. Archived from the original on 2009-03-16. Retrieved 2009-04-07.
- "People Are Really Excited That McDonald's Shamrock Shakes Are Back". Travel & Leisure.
- "Ultimate Shamrock Shake Guide". Gluttoner. Retrieved 18 October 2012.
- "McDonald's mint flavoured Shamrock Shake returns to Irish stores". Irish Mirror. 2019-02-15. Retrieved 2019-06-20.
- Saelinger, Tracy. "McDonald's has 4 new chocolaty Shamrock Shakes and we tried them all". Retrieved 2019-02-21.