St Patricks Day Hat
Green Beer, Guinness, Corn beef and cabbage, and St Patricks Day Hats
Saint Patrick's Day, also called St. Paddy's Day or Paddy's Day, is both a religious and secular holiday celebrating Saint Patrick (who lived AD 385–461), and is one of the patron saints of Ireland. It's generally celebrated on the 17th of March, although is sometimes moved to avoiding conflicting with Holy Week as it did in 1940, 2008, and will again in 2160.
It's celebrated worldwide by both those of Irish descent and just about everyone else. I've celebrated it on 3 continents so far, and I'm not remotely Irish!
Celebrations are extremely festive and center around alcohol, especially beer such as Guinness, Irish Whiskey, and Irish Cream, eating Irish foods like corn beef and cabbage, and the color green.
People wear plenty of green. Chicago dies the Chicago River green. Manchester has a two week Irish festival where most everyone wears green.
There is not much more festive, to go along with your pint of Guinness or green beer, than a St Patrick's Day Hat. It signals to everyone that you are in the spirit, a reveler, and even better, people may offer to buy you drinks!
There are plenty of St Patrick's Day hats you could wear - let's look at a few awesome ones.

This Adult Leprechaun Hat is sure to make you the hit of Saint Patrick's Day!
It comes in various adult sizes, and should last for many St. Patricks days. There isn't much more Irish than a Leprechaun, except maybe a Leprechaun drinking a beer on Saint Patricks Day, which is probably easily arranged should you be sporting this beauty!

I'm also partial to this St. Patrick's Day Derby Hat.
This is a very good quality, wool felt, green derby hat.
Whether for a party, a parade gathering, visiting the pub, or anything else, this derby will be an item that you can use for St. Patty's for years to come.
The Bright Emerald Green will have you standing out from the crowd!

Last but not least, this farcical and hilarious St. Patrick's Day Giant Leprechaun Hat
will certainly get you noticed anywhere you may be on Saint Paddys.
Unlike the other two hats, it's less likely you'll wear this one in the off season, although you certainly could, for example while hunting for pots of gold and drinking a pint or two.
My kids absolutely love it!
Unfortunately it can only be shipped to the contiguous 48 states, and you may not look as comical as the male model wearing it in the picture.
Spice up your Saint Patricks day with a Saint Patricks day hat! You'll stand out from the crown, whether you're in church or with a bunch of drunken buffoons in the pub!
Also check out these other Saint Patricks Day Resources.