The midfielder has joined the Championship club until the end of January.
The 19-year-old has yet to make an appearance for the Reds but is a regular in the U21 side, and the Echo report that he has been invited to train with the first-team on several occasions.
He moves to a Wednesday side that is enjoying life in the Championship currently. After a slow start - that saw the Owls collect just one win in their opening seven league games - Carlos Carvalhal has guided his men on a run that has seen them lose once in their last 13 games.
As well as occupying eighth place in the division, just one point off a play-off spot, the Yorkshire side have gone to St James' Park and beaten Newcastle in the Capital One Cup, before humiliating Arsenal in the same competition. With the cup run stretching the squad, Marsh may be able to prove to Jurgen Klopp that he has the potential to make the grade at Anfield.
The striker-turned-central midfielder will be hoping to emulate Jordon Ibe, who used his loan spell at Derby County to showcase his talent, and quickly found himself very much involved with the first-team upon his return.