“I’m not Irish, but my coffee is” (or “I’m not Irish, but my coffee might be” is a St. Patrick’s Day saying that has been printed on many images. The speaker likes Irish coffee.
     
“I’m not Irish but my coffee is” was printed in the Cincinnati (OH) Enquirer on March 8, 2006. “I’m not Irish, but my coffee is” was posted on Twitter by The Spaniard on March 17, 2009. “I’m not Irish, but my coffee is. (@RanGt)” was posted on Twitter by Savvy on February 5, 2011. “i’m not irish, but my coffee is” was posted on Twitter by toj on March 5, 2015. “I’m Not Irish But My Coffee Is Funny Novelty St. Patrick’s Day Gifts: Lined Notebook Journal” was posted on Google Books in 2019.
   
“I’m Not Irish But My Coffee Might Be Funny St Patricks Day T-Shirt” was posted on Amazon.com on February 26, 2020.
 
   
Wikipedia: Irish coffee
Irish coffee (Irish: caife Gaelach) is a caffeinated alcoholic drink consisting of Irish whiskey, hot coffee and sugar, which has been stirred and topped with cream (sometimes cream liqueur). The coffee is drunk through the cream.
       
Newspapers.com
8 March 2006, Cincinnati (OH) Enquirer, “Staff Question of the Week: How Irish are you?,” Cin Weekly, pg. 6, col. 4:
TYLER THOMPSON
(...) 
I’m not Irish but my coffee is.
Twitter
The Spaniard
@thespaniard
I’m not Irish, but my coffee is. Happy St Paddys Day. Todays first movie: In Bruges. Awesome!!!
12:20 PM · Mar 17, 2009
   
Twitter
Savvy
@SavvyLY
I’m not Irish, but my coffee is. (@RanGt)
12:10 PM · Feb 5, 2011
   
Twitter
Samodean
@Samodean
No, I’m not Irish, but my coffee is.
8:52 AM · Mar 17, 2011
   
Twitter
Warren S
@WazzaYEG
I’m not Irish, but my coffee is. Happy St. Patty’s Day! #observe #celebrate #forgetthewholeday
12:09 PM · Mar 17, 2013
   
Twitter
toj
@tojo_youknow3
i’m not irish, but my coffee is. @ hipster ave • dublin, ireland https://instagram.com/p/z218q8qVT6/
1:58 PM · Mar 5, 2015 from Dublin City, Ireland
   
Twitter
Trouble4Sure
@OlderNot2Wiser
I’m not Irish, but my coffee is. #lettheboozingbegin
6:47 PM · Mar 3, 2017
 
Twitter
Happy Mother Day 2019
@Thefirdaydeals
(Celebrate St. Patrick's Day Together “I'm Not Irish, But My Coffee Is” 1…) http://saintpatrickday.info/celebrate-st-patricks-day-together-im-not-irish-but-my-coffee-is-1/
(The saying is shown on a coffee mug.—ed.)
3:11 AM · Mar 2, 2018
 
Google Books
I’m Not Irish But My Coffee Is
Funny Novelty St. Patrick’s Day Gifts: Lined Notebook Journal
By Red Pencil Publishing · 2019
         
Amazon.com
Brand: The Weird Shop
I’m Not Irish But My Coffee Might Be Funny St Patricks Day T-Shirt
Package Dimensions ‏ : ‎ 10 x 8 x 1 inches; 4.8 Ounces
Department ‏ : ‎ mens
Date First Available ‏ : ‎ February 26, 2020
Manufacturer ‏ : ‎ The Weird Shop
 
Twitter
Dallas Artworks
@pdallasart
I’m not Irish but my coffee is St Paddy Day T-Shirt Lucky Green Clover Design… https://amazon.com/dp/B08THYFB7X/ref=cm_sw_r_tw_dp_A3C6F49MGJJFCRV674PP via @amazon
#StPatricksDay
6:22 PM · Jan 28, 2021
   
Twitter
Becca
@hrtbeccaweather
I’m not Irish, but my coffee is. ☘️🇮🇪☕️🌈
Leprechaun Fuel Irish Coffee Mugs available on #DoReMiDesignsCo NOW!
https://etsy.com/DoReMiDesignsCo/listing/968565733/leprechaun-fuel-irish-coffee-mug?utm_source=Copy&utm_medium=ListingManager&utm_campaign=Share&utm_term=so.lmsm&share_time=1614107329951
#Etsy #Handmade #SmallBusiness #stpatricksday #stpattysday #shamrock #leprechaun #Ireland #Irish #Coffee #Irishcoffee #coffeetime
2:09 PM · Feb 23, 2021
   
Twitter
On The Grind Coffee
@OTG_Coffee
🍀I’m not Irish, but my coffee is!🍀
1:00 PM · Mar 8, 2021
 
Bustle
21 St. Patrick’s Day Instagram Captions That’ll Make Your Friends Laugh
“The paddy don’t start till I walk in.”
by Jessica Booth and Mia Mercado
Updated: March 17, 2021
Originally Published: March 14, 2019
(...)
14 I’m not Irish, but my coffee is.
If there were any occasion to spike your coffee, it’s St. Patrick’s Day.
     
Twitter
lisa lantz
@lisalduhon
🍀I’m not Irish, but my coffee is.🍀#ruffcutspurrfectstyles #jakemarceaux #yorkie @ Ruff Cuts & PurrFect Styles https://instagram.com/p/CbMKSKpMY0L/?utm_medium=twitter
11:33 PM · Mar 16, 2022 from Jennings, LA
 
The Pioneer Woman
115 Best St. Patrick’s Day Instagram Captions That Are Better Than a Pot of Gold
“I’m not Irish, but I still pinch!” 😂🍀
By Erin Cavoto Published: Mar 16, 2023
(...)
I’m not Irish, but my coffee is.
 
Twitter
Fries Tallman Lumber
@FriesTallman
I’m not Irish, but my coffee is 🍀
#LetsPaddy
1:03 PM · Mar 17, 2023