"Justice League" and "Aquaman" star Jason Momoa is accused of owing a ton of money to someone more powerful than King Neptune ... Uncle Sam.
According to official records, the IRS slapped Momoa with a Federal tax lien for $138,378.88 in unpaid taxes.
The tax bill stems from income the actor earned in 2015.
The documents state that if the outstanding debt isn’t settled-up soon, they will begin the process of seizing his assets & property.
Momoa shouldn’t have too much trouble paying off the debt though ... two big superhero blockbusters have a habit of bringing in a fat payday.