Gary MacPherson was found guilty of 22 charges, including rape, on 12 May 2025 following a trial at the High Court in Paisley.
The 58-year-old, of Saltcoats, committed the offences between 2005 and 2022 at various locations including at his former home in Paisley.
The prosecution led evidence from the victims, which detailed a pattern of offending behaviour by the accused as he tried to gain their trust.
The court heard how MacPherson kitted his home out with things that children enjoy including a pool, a hot tub, a cinema room, a trampoline and various pets.
He lured in one of the victims after sending her messages about his dog Bonnie on social media.
He told several of the victims not to disclose the abuse as they would get him into trouble.
The offending also included taking pictures of the girls without their consent and stalking behaviour.
The youngest child was six-years-old when the abuse began.
On 30 June 2025 at the High Court in Paisley, MacPherson was given a 17-year extended sentence with 13 years in custody.
His name has been added to the sex offenders register indefinitely.
Non-harassment orders, banning MacPherson from contacting or attempting to contact seven of the victims, were also granted for an indefinite period.
Fiona Kirkby, Procurator Fiscal for High Court Sexual Offences, said: “Gary MacPherson inflicted unimageable trauma as he systematically moved from victim to victim.
“The evidence led by our specialist prosecutor demonstrated a clear pattern of grooming behaviour that allowed him to gain access to these children.
“It is thanks to them reporting their experiences that MacPherson will now face the consequences of his depraved actions while also protecting others from harm.
“This prosecution sends a clear message to those who commit this type of offending - you cannot hide from justice, and we will do everything within our power to ensure you are held accountable.
“I would urge anyone affected by sexual abuse to report it, regardless of how long ago it took place. You will be listened to and supported as we seek to protect communities in Scotland by prosecuting those responsible.”