Southampton have signed Kevin Danso from FC Augsburg on a season-long loan, with an option to buy the centre-back.
The 20-year-old defender is the final incoming Premier League transfer deadline day deal to be announced, hours after Thursday's window closed.
The Austria under-21 international returns to England after starting his youth career at MK Dons.
Forwards Che Adams and Danny Ings and winger Moussa Djenepo are also summer arrivals at St Mary's.
Adams, 22, was signed from Birmingham City for £15m and Ings, 26, made his loan move form Liverpool permanent in a £20m deal, while Mali international Djenepo, 20, left Standard Liege for the Saints after agreeing a four-year deal.
"I'm delighted to join a club that has produced a lot of great players and I'm looking forward to working with such a great coach in Ralph Hasenhuttl as well," Danso said.
A busy transfer deadline day saw the Premier League spending for the summer increase to £1.41bn, just short of the £1.43bn record set in 2017, according to Deloitte.