Meaning
What does Not today, Satan mean?
Not today, Satan is the saying of the occasional church goer, who believes in the existence of god and devil, but don’t obsess about religion or the righteous life so much, thus having a reason to be vary of Satan and his ambushes.
When you manage to avoid failure and shame, by evading the malevolent forces of darkness, congratulations! You are entitled to say the iconic phrase; not today, Satan! Not today!
Origin
What's the origin of Not today, Satan?
The expression comes from the Tv Show, RuPaul’s Drag Race, a series, in which men are in a contest to become the next drag queen of the show.
The inconic phrase was said in the final episode of the sixth season, by the participant Bianca Del Rio. It became an instant hit and people referenced it all over the internet.
Spread & Usage
How did Not today, Satan spread?
We may see it on “funny” workplace stickers, signs or merchandize, influencers put out to make some extra dough with their “brand”.
Since then, it faded out of the common knowledge and is mostly used by the Karens between two meetings with managers, exclaiming to their nemesis quietly; “Not today, Satan”. Urban Dictionary added the first definition on the phrase in 2015.

External resources
- Urban Dictionary – Urban Dictionary: Not today Satan, not today.