Southampton have completed the signing of Celtic midfielder Stuart Armstrong.

Armstrong, 26, has signed a four-year deal at St Mary's after a fee in the region of £7m was agreed between the two clubs.

The Scotland international, who played a key role in Celtic's title success last term, becomes Southampton's first signing of the summer.

"Every season, I put demands on myself to create and score goals. I hope going forwards from here that it will be the same this term at St Mary's," he said.

"Southampton seems a really good fit for me. Watching from afar, I really enjoy the attractive football that they play and I'm very happy to be here."

Saints boss Mark Hughes added: “Stuart is a player who we have admired for some time, and I am delighted we have been able to bring him here, especially given the competition we faced to sign him.

"It is important we add a greater goal threat to the team as a whole, and to our midfield specifically, and Stuart's record of scoring and creating makes him an extremely exciting addition in that area."