The Republic of Ireland Under-21 international arrives at Huish Park to bolster the Glovers’ defensive options.
Offering versatility at the back, the 20-year-old goes straight into the squad for Saturday’s Emirates FA Cup third round tie with Bradford City.
Equally at home at right-back or centre-half, Whelan becomes Yeovil’s second January signing following the arrival of midfielder Jared Bird on Thursday.
The youngster was previously with Crewe Alexandra’s prestigious Academy before joining the Reds at Under-10 level.
Whelan made his Liverpool Under-18s debut during the 2013/14 season and has since found himself a regular within the Under-23 setup, recently penning a new deal at Anfield.