Of course, the 31-year-old lit the internet on fire 13 years ago ... when she busted out the iconic moves to the Cali Swag District hit at a basketball game.

The clip garnered millions of views and stole the hearts of horny kids all over the world ... so it's only fitting Upton reprised her role for her first post on the social media platform.

The vid starts by showing Upton search "Teach Me How To Dougie" on DuckDuckGo ... before letting loose with her moves.

"Teach me how to TikTok…? #dougie," Justin Verlander's wife said in the caption.

Safe to say she hasn't lost a step in over a decade ... duplicating the dance for her followers just like she did back in the day.

BTW -- she currently only has just over 500 people tuning in to her page ... but we assume that number is going to explode now that she's gone public with the profile.

So ... Cat Daddy next??