The 24-year-old has enjoyed a stellar season for the Italian giants, racking up 44 appearances across all competitions while establishing himself as one of the top centre-backs in Europe.
The Slovakian's performances in Serie A have attracted the attention of a number of top clubs in recent months, including Real Madrid, who were thought to be leading the race for his signature.
Skriniar has insisted there is no substance to those rumours, however, telling Goal and DAZN he knew nothing of the interest from the Spanish giants.
United were also reportedly keeping a close eye on Skriniar, but he has ultimately decided to extend his stay with Inter until 2023.
The club wrote on their official website on Thursday: "Milan Skriniar and Inter have the same aims. And this is why FC Internazionale Milano has extended the Slovakian defender’s contract until 30 June 2023."
Luciano Spalletti's side have had a mixed 2018-19 campaign, dropping out of contention for major trophies but remaining relatively consistent in Serie A.
Inter are on course for a top-three finish with two matches remaining, with a tough trip to second-placed Napoli up next on Sunday.
They will then wrap up their season with a home clash against Empoli a week later and Skriniar is likely to retain his place in the starting line-up.
The Nerazzurri have managed to keep 15 clean sheets in total this term with the towering defender leading by example at the back and supporters can now look forward to many more years of service from a standout performer.
Skriniar also spoke to Goal about a possible captaincy role in the near future, insisting he will continue to give his all to Inter's cause with or without the armband.
“I don’t think that something suddenly changes just because you have the armband," he said. "Obviously, you have some extra responsibility, but whether you have the armband or not you always have to give everything on the pitch.
“You always have to do that, it doesn’t matter whether you play one minute or the whole match.
“And if you are the captain then you still do the same things in order to help the team.”