The media magnate's defence team had previously announced their intention to appeal the July verdict, which saw the former premier sentenced to seven years in jail and banned from holding public office.
The punishment was suspended pending the appeal process, which is likely to take years.
The billionaire has denied having sex with Ruby at what prosecutors had described as erotic parties held at his luxury residence outside Milan.
Witnesses said the gathering featured nudity and strippers dressed up as nuns.
Berlusconi was accused of paying for sex on several occasions with Moroccan-born Ruby, a then 17-year-old exotic dancer and busty glamour girl whose real name is Karima El-Mahroug.
He was also accused of having called a police station to press for El-Mahroug's release from custody when she was arrested for theft.
His defence claimed he believed El-Mahroug was the niece of former Egyptian president Hosni Mubarak and wanted to avoid a diplomatic incident. But prosecutors insisted that was a bid to conceal their relationship.
The appeal will centre on Berlusconi's claim that "the accusations are unfounded," the lawyers were quoted as saying by the ANSA news agency.
The scandal-tainted 77-year-old risks a fresh, parallel trial after a Milan court accused him of corrupting witnesses by paying women monthly sums to testify that his parties were just innocent dinners.
The three-time premier – no stranger to the courts during his political career – was also sentenced to a year in prison for tax fraud last year which saw him ousted from parliament and stripped of his protection from the law.