Cast and crew, fans and media outlets all celebrated. Here are some of those tributes.
From EW Supernatural: Jensen Ackles, Jared Padalecki pick Sam and Dean's road trip playlist.
Zap2It listed 11 best ‘Supernatural’ sidekicks, from Crowley to Castiel.
IGN named Supernatural's 9 Best Villains. Their pick for number 1, our old adversary Azazel!

TV Guide picked Supernatural: The Best Music Moments From the Road So Far. TV Guide also shared this video, Inside the Impala. Can't leave Baby out of a Supernatural celebration!
TV Guide also tweeted this:
Happy #SupernaturalDay! Here's our listing for the first episode, back on September 13, 2005 https://t.co/FfjekjZMco pic.twitter.com/RtyvIZhlx8
— TV Guide Magazine (@TVGuideMagazine) September 13, 2016
From TVLine we got Supernatural Day: Celebrating the Best Episode From Each Season.

TV Fanatic decided to prove that great magazines think alike and picked Supernatural: The Best Episodes... by Season!!.

TV Addict went further with SUPERNATURAL Day: Our Favorite Episodes, Angel & Demon Scenes, Winchester Scenes, Guest Characters and More.

KSite looked back at the first article they ever wrote about Supernatural and linked to their Supernatural forum.
Nerds and Beyond did a think piece on Supernatural Day: Celebrating More Than Just a Television Show .

Even Olive Garden got into the spirit. (Thanks all-spnlivejournal for the tip.)
We pasta-fied some of our fav Supernatural quotes. Now it's your turn! #SupernaturalDay #SPNfamily pic.twitter.com/c6tKdhvvda
— Olive Garden (@olivegarden) September 13, 2016
International Business Times reported ‘Supernatural’ Turns 11! Series Stars Jared Padalecki, Jensen Ackles, Misha Collins And Mark Sheppard Thank Fans [VIDEO].
BuddyTV had the same idea See How Jared and Jensen Celebrated 'Supernatural' Day including this gift from the CW.
Supernatural The Crossroads did a tribute to Supernatural Day as well (note NSFW) - Thanks Wednesday for the heads up.
Jared and Jensen used the day to launch a new charity campaign. From Nerds and Beyond Jared Padalecki and Jensen Ackles Announce New Campaign – Family Always Has Your Back!.

CelebMix added Jared Padalecki and Jensen Ackles Celebrate Supernatural Day with New Clothing Campaign..

The campaign can be found here.
Hit 'Next' to see Tweets from the Cast and Crew.
Both current and former members of the Cast and Crew tweeted in support of our show.
12 years ago, a dangerous cult based on demonology, witchcraft, classic cars was formed. Celebrate #SupernaturalDay! pic.twitter.com/ayLU11siCG
— Misha Collins (@mishacollins) September 13, 2016
Eight seasons of joy. My dream job. My dream cast & crew. My friends. My #SPNFamily. My life. Happy #SupernaturalDay pic.twitter.com/zBKnr3xHeZ
— Mark Sheppard (@Mark_Sheppard) September 14, 2016
I love you #SPNFamily - you changed my life. Thank you from the bottom of my heart ❤️ and #BabysBooti ❤e pic.twitter.com/o1tlNfNNsf
— Ruth Connell ♕ (@RuthieConnell) September 13, 2016
Happy #SupernaturalDay, lovely peeps! #WhatALongStrangeTripItsBeen #Gratitude pic.twitter.com/mhKqhsZSje
— Samantha Smith (@SamSmithTweets) September 14, 2016
Found moose. Looking for squirrel. #SupernaturalDay pic.twitter.com/qA8FS8BD4S
— ΞXΓЯΞMΞ ҜIM (@kimrhodes4real) September 13, 2016
#SUPERNATURALDAY #SPNFAMILY pic.twitter.com/UXlEOUXNEi
— matt cohen (@mattcohen4real) September 13, 2016
4 ever grateful 2 #Supernatural. So proud 2 b part of this family. Happy #SupernaturalDay And may Chuck be with you pic.twitter.com/QCfrNnR6jg
— Adam Glass (@AdamGlass44) September 13, 2016
Happy #SupernaturalDay!
— Robbie Thompson (@rthompson1138) September 13, 2016
(EVERYDAY IS #SUPERNATURALDAY) pic.twitter.com/25lbzaXCSK
Happy #SupernaturalDay! On this day those many years ago, like most days, I was thinking, "God, I hope @therealKripke doesn't fire me."
— Sera Gamble (@serathegamble) September 13, 2016
From the big Kahuna himself
How'd I feel 11 yrs ago? Like a nervous parent. Just wanted people to watch. Glad you did, #SPNFamily. THANK YOU! Happy #SupernaturalDay.
— Eric Kripke (@therealKripke) September 13, 2016
Finally, from the Hillywood girls
In honor of #SupernaturalDay, one of my favorite scenes to film on #SupernaturalParody! ? ? https://t.co/1UvRP65r9T pic.twitter.com/SUbCLo86vo
— Hilly Hindi (@HillyHindi) September 13, 2016
Thanks to the cast, crew, writers and fans who made this day possible! I'm looking forward to many more Supernatural Days in the future. What did you think of it? Please add any tributes to Supernatural Day that I may have missed!