The 23-year-old was told he was surplus to requirements this week. He played for the capital club in a friendly win over Berwick Rangers but manager Neil Lennon confirmed that he won’t make the first-team.
“I’m very fond of Sammy too,” he said, “but it’s very difficult with the midfield we have at the minute.”
Stanton has spent the last 18 months on loan at Livingston and most recently Dumbarton, where he played 27 times as the part-time side secured second tier survival. He has scored seven goals in 70 games for Hibs.
“I am excited to join United,” he told the club’s website. “It is a fantastic opportunity for me at a great club and I hope to help United secure the Championship title.
“It is important at my age that I am playing week in, week out and to be offered the opportunity at a club like United is great. I cannot wait to get on the park and show the United fans what I can bring.”
He will link up with former Hibs team-mate James Keatings who was Ray McKinnon’s first summer recruit.
The United boss said: “We have been busy in recent days and securing Samuel rounds up a fantastic few days.
“Everything we are currently doing is geared towards ensuring we have a strong matchday squad and Samuel is a great young, hungry footballer who brings real attacking ability.
“We are getting close to where we want to be, but I am hoping to add a few more before the league campaign begins.”