The 18-year-old playmaker has signed a three-year deal at Tannadice; his contract at the Ibrox club expired this summer.
Much is expected of the Scotland under-19 internationalist and the youngster insists he will be able to cope in the SPFL Premiership next season. "I have watched how the younger players at United are allowed to develop in the first team and that has been a big reason in my decision to join the club," he said.
"The opportunity to play in the Premiership next season was also something I could not turn down.
"I believe I am ready to play in the first team but I have to show the manager that is the case.
"I cannot wait to meet my new team-mates and start pre-season."