When Did God Show Up in Supernatural?

Chuck may have been revealed as God in Season 11 of Supernatural but the writers set that up way before starting in Season 4 of the beloved CW series.
Buckle Up for Supernatural: Where Monster Hunting is a Family Business. Hit the gas and chase demons with the Winchester brothers in Supernatural!

Supernatural': Sam Trapped in Hell With Lucifer — Season 11 Fall Finale Recap – TVLine

When Did God Show Up in Supernatural?

You Have Received A Supernatural Manifestation Of The Faith Of God

Supernatural Season 15: Rob Benedict on Why Sam and Dean Forgot About Adam - TV Guide

Stream Supernatural - Fare Thee Well (Dink's Song)- Rob Benedict as Chuck Shurley/God by WaterTowerMusic

God (Supernatural), Villains Wiki

Shirtless Sammy — Is Chuck God? Exploring the Theory

Supernatural (season 15) - Wikipedia

Supernatural stars hint if God will be evil in final season

Naturally Supernatural: God may be closer than you think: Best, Gary: 9780620348140: : Books

God, Supernatural Wiki