May 1st
Law Day
National Loyalty Day
National Chocolate Parfait Day
National Mother Goose Day
Silver Star Service Banner Day
National Melanoma Monday – First Monday in May
National School Principals' Day

May 2nd
National Life Insurance Day
National Truffle Day

May 3rd
National SAN Architect Day*
National Textiles Day*
National Chocolate Custard Day
National Garden Meditation Day
National Lumpy Rug Day
National Paranormal Day
National Raspberry Popover Day
National Specially-Abled Pets Day
National Two Different Colored Shoes Day

May 4th
Bird Day
National Candied Orange Peel Day
National Orange Juice Day
National Renewal Day
National Star Wars Day
National Weather Observers Day
National Day of Prayer – First Thursday in May
National Day of Reason – First Thursday in May

May 5th
National Astronaut Day*
World Password Day*
National Cartoonists Day
Cinco de Mayo
National Hoagie Day
National Totally Chipotle Day
National Space Day – First Friday in May
National Military Spouse Appreciation Day – Friday Before Mother's Day
National Provider Appreciation Day – Friday Before Mother's Day

May 6th
National Beverage Day
National Crepe Suzette Day
National Nurses Day
Join Hands Day – First Saturday in May
National Bombshells' Day – First Saturday in May
National Scrapbook Day – First Saturday in May
National Start Seeing Monarchs Day – First Saturday in May
National Train Day – Discontinued by Amtrak in 2016

May 7th
National Barrier Awareness Day
National Packaging Design Day
National Paste-Up Day
National Roast Leg of Lamb Day
National Homebrew Day
Free Comic Book Day
National Lemonade Day – First Sunday in May

May 8th
National Coconut Cream Pie Day
National Have A Coke Day
National Student Nurse Day
National Women's Checkup Day – Second Monday in May

May 9th
National Butterscotch Brownie Day
National Lost Sock Memorial Day
National Moscato Day
National Teacher Appreciation Day – Tuesday of the First Full Week in May

May 10th
National Lipid Day*
National Shrimp Day
National Clean Up Your Room Day
National Bike to School Day – Changes Annually
National School Nurse Day – Wednesday of National Nurses Week
National Receptionists Day – Second Wednesday in May
National Third Shift Workers Day – Second Wednesday in May

May 11th
National Foam Rolling Day*
National Twilight Zone Day

May 12th
National Fibromyalgia Awareness Day
National Limerick Day
National Nutty Fudge Day
National Odometer Day

May 13th
National Crouton Day
National Apple Pie Day
National Frog Jumping Day
National Fruit Cocktail Day
National Babysitter's Day – Saturday Before Mother's Day
National Birth Mother's Day – Saturday Before Mother's Day
National Archery Day – Second Saturday in May
National Cornelia De Lange Syndrome Awareness Day – Second Saturday in May
National Miniature Golf Day – Second Saturday in May
National Stamp Out Hunger Food Drive Day – Second Saturday in May

May 14th
National Buttermilk Biscuit Day
National Dance Like a Chicken Day
National Underground America Day
Mother's Day – Second Sunday in May

May 15th
National Chocolate Chip Day
National Nylon Stocking Day
Peace Officers Memorial Day

May 16th
Honor Our LGBT Elders Day
National Biographer's Day
National Coquilles Saint Jacques Day
National Love a Tree Day
National Piercing Day
National Sea Monkey Day

May 17th
National Cherry Cobbler Day
National Pack Rat Day
National Walnut Day

May 18th
National Cheese Souffle Day
National HIV Vaccine Awareness Day
National No Dirty Dishes Day
National Visit Your Relatives Day

May 19th
National Devil's Food Cake Day
National May Ray Day
National Bike to Work Day – Third Friday in May
National Defense Transportation Day – Third Friday in May
National Endangered Species Day – Third Friday in May
National Pizza Party Day – Third Friday in May
NASCAR Day – Third Friday in May

May 20th
National Be a Millionaire Day
National Pick Strawberries Day
National Quiche Lorraine Day
National Armed Forces Day – Third Saturday in May
National Learn to Swim Day – Third Saturday in May

May 21st
National American Red Cross Founder's Day
National Memo Day
National Strawberries and Cream Day
National Waitstaff Day

May 22nd
National Buy a Musical Instrument Day
National Maritime Day
National Vanilla Pudding Day

May 23rd
National Lucky Penny Day
National Taffy Day

May 24th
National Escargot Day
National Scavenger Hunt Day
Aviation Maintenance Technician Day
Emergency Medical Services for Children – Wednesday of Emergency Medical Service Week

May 25th
National Brown-Bag It Day
National Missing Children's Day
National Tap Dance Day
National Wine Day
Towel Day

May 26th
National Blueberry Cheesecake Day
National Don't Fry Day – Friday Before Memorial Day
National Heat Awareness Day – Last Friday in May

May 27th
National Cellophane Tape Day
National Grape Popsicle Day

May 28th
National Brisket Day
National Hamburger Day

May 29th
National Coq Au Vin Day
National Paperclip Day
Memorial Day  – Last Monday in May

May 30th
Loomis Day
National Hole In My Bucket Day
National Mint Julep Day
National Water a Flower Day

May 31st
National Macaroon Day
National Save Your Hearing Day
National Speak in Sentences Day
National Senior Health and Fitness Day