The 19-year-old scored just once in 18 appearances for the Tykes.
"We're really pleased, though, that it is worked out for us in January.
"He will definitely add a lot to the team – he's a natural finisher but he's also got great link play and good pace and physicality."
BREAKING!#MKDons have signed highly-rated @ChelseaFC striker @IUgbo on loan until the end of the season.
Full story: https://t.co/Z5kuarGbet#COYD
— MK Dons FC (@MKDonsFC) January 4, 2018