The event take place Thursday, April 21 from 11 a.m. to 3 p.m.
Customers are limited to one per person and in-shop dining only on select sandwiches.
You can check to see if your local Jimmy John's restaurant is taking part here.
Jimmy John's says it's just a way to say thanks to their fans.
$1 subs at Jimmy John's from 11:00am-3:00pm on April 21st, RT to save a life. 😋 #JJDollarSubDay
— Jimmy John's (@jimmyjohns) April 18, 2016