The 19-year-old attacker was poached by Villa from Albion's academy in a reported £1million move as a 16-year-old but now returns to the club with which he spent his formative years on loan for the remainder of the season.
It is understood there was other interest in taking Jimoh-Aloba on loan, including from Albion's Championship rivals Preston North End.
Leicester City were also potential suitors, but the Erdington-based youngster was determined to move back to his former club and try to help them out of the mire near the foot of the Championship.
He checks in on deadline day after recently netting a first senior goal in Villa's Europa League victory over RB Salzburg last week and becomes Albion's third signing of the January window.
Jimoh-Aloba arrives as an existing on-loan Villa attacker, Samuel Iling-Junior, is poised to depart The Hawthorns.
His loan is to be cancelled and Iling-Junior is heading out to Italian Serie A strugglers Pisa.