The teenager, who cannot be identified, appeared before Leeds Crown Court over the collision on Stonegate Road, Meanwood, on November 25.
The charges relate to the deaths of Ellis Thornton-Kimmitt, 12, Elliott Thornton-Kimmitt, 14, Darnell Harte, 15, Robbie Meerun and Anthony Armour, both 24.
A judge warned him that it was likely that he would be “locked up for quite a long time.”
The youngster appeared before the court via a video link from custody.
The slightly-built, dark haired teenager appeared on screen with his arm in a sling during the 20-minute hearing.
He spoke to confirm his name, date of birth and nationality before the five charges were put to him by the court clerk.
Each charged related to causing death by dangerous driving, on November 27, 2017, by driving a Renault Clio dangerously.
The defendant entered a guilty after each charge was put to him.
People wept in the public gallery as the teenager entered the guilty pleas.
Patrick Palmer, prosecuting, told the court a full collision investigation report was needed before sentencing could take place.
The court heard time was also needed to prepare youth offending reports.
The Recorder of Leeds, judge Peter Collier, QC, adjourned the case until January 26, when the defendant will be sentenced.
He told the teenager: “The prosecution will be putting together paperwork to describe what happened on that night so that we have got a full account from an expert.”
He added: “In the meantime the youth offending team will be talking with you and preparing a report for me about you, about your background and what you think and feel about what happened on that night, and any proposals they have.
“This is a very serious thing you have admitted and it is almost inevitable that there will be a custodial sentence.
“Effectively, you will be locked up for quite a long time. That is something I will have to think very carefully about.”