The 20-year-old, who was Neil Redfearn's first signing as Millers boss in October, has featured six times for the Millers in both the left-back and left-sided midfield positions.
He excelled in his debut against Reading, but found himself out of the team before coming on as a half-time substitute against Leeds on Saturday following Joe Mattock's injury.
With Mattock set for a spell on the sidelines with a hamstring strain, the Millers have moved to keep Toffolo at the New York Stadium until the turn of the year.
Happy to have extended my loan at @OfficialRUFC on the back of a big win at the weekend! Looking forward to Saturday! 👍🏼— Harry Toffolo (@Harry_Toffolo) November 23, 2015
Toffolo said: “For me personally, I obviously came to Rotherham to gain regular first team football, and I am grateful for that opportunity,
“The Championship is a tough league. It’s relentless at times, and requires you to hone your game both mentality and physically. I know it’s a bit of a cliché, but anyone really can beat anyone on their day, which is why it’s important to string together a couple of good results.
"Confidence breeds confidence, and with a bit more fortune, the only way for Rotherham is up."
