Edited March 14, 2018
at 02:26 PM
Since tomorrow is National Pi Day, 3.14, and there were a few offers last year, I thought I'd post those that I've come across so far for tomorrow. Check out each site for more details, exclusions, etc.
Your Pie - $3.14 pizzas. Limit one/person Link [facebook.com]
Blaze Pizza - $3.14 pizzas. "Limit one $3.14 pie per guest." Link [blazepizza.com]
Pieology - Sign up for Pie Life to get a coupon for a BOGO for $3.14. Link [pieology.com]
Villa Italian Kitchen - Get a whole cheese Neapolitan pizza for $3.14 when you fill out the form. Link [villaitaliankitchen.com]
Hungry Howie's - Get a medium 1-topping pizza for $3.14 when you buy Howie Bread at regular menu price. Link [hungryhowies.com]
Cici's Pizza - Buy one Adult buffet, get one for $3.14 with coupon [fbmta.com]
Bojangles' - 3 Sweet Potato Pies for $3.14. Link [bojangles.com]
Whole Foods - $3.14 off large bakery pies. Link [wholefoodsmarket.com]
Boston Market - Buy one pot pie and a drink, get one pot pie free with coupon [bostonmarket.com]
Kroger - Bakery pies for $3.14 on 3/13 and 3/14 with card. Link [facebook.com]
Papa Murphy's - Buy a large, thin one-topping pizza for $3.14 for online orders. YMMV. Shows up as the first option under Classics & Specials as "Pi Day Pizza." Known to work in IA, TN, and AL. Link [papamurphys.com]
Pie Five - $3.14 pizzas. Limit one/person. Link [e2ma.net]
I'll try to keep the OP updated, but feel free to add to the Wiki.