It's widely known that wearing green is a must on St. Patrick's day. It's a fun tradition that brings joy and luck to all ages. It's also a day filled with green beer and Irish whiskey, and that's a tradition that we always partake in. No matter how you plan on celebrating this year, you can still have some fun with your St. Patty's day outfit. Here are our favorite St. Patrick's day shirts that you need this year!