Elijah Wood is officially a married man ... tying the knot with his longtime partner Mette-Marie Kongsved.

The "Lord of The Rings" star set off alarms recently when he referred to Mette-Marie as his wife on a podcast ... so we did some digging and found out the couple has a marriage license on file in Los Angeles County.

Thing is ... Elijah and Mette-Marie chose a confidential marriage license ... so it's unclear when exactly they tied the knot.

Elijah called Mette-Marie his wife earlier last month on an episode of the "Inside of You" podcast ... with host Michael Rosenbaum also referring to the film producer as Elijah's wife.

The couple are notoriously private about their relationship ... they went public with their romance in January 2018 and have two children together, a son and a daughter.

As we reported ... witnesses say Elijah and Mette-Marie got married in Sweden on New Year's Eve in what was described to us as an intimate ceremony with around 80 friends and family.

Now we know they're at least legally hitched in the States.

Mazel Tov!!!