MK Dons have signed Celtic's Aidan Nesbitt and Wigan's Alex Gilbey for undisclosed fees, while Bristol City's Scott Golbourne has joined on loan.
Scotland Under-21 winger Nesbitt, 20, has been on loan at Partick and Morton and has signed a two-year contract.
Left-back Golbourne, 29, won League One with Wolves in 2013-14 and will stay with the Dons until mid-January.
Ex-Colchester midfielder Gilbey, 22, has agreed a three-year deal, leaving Wigan after just one full season.
"Alex has been a player we've admired for a long time. We've worked hard to get the deal done - he is exactly the type of player we are after," said boss Robbie Neilson.
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