Head of Football Chris Pelchen said Dal Santo had been a wonderful contributor throughout his career.
"Nick has been an important part of the St Kilda Football Club since his debut in 2002," Pelchen said.
"He has been a valued and respected player with the Saints and it was an extremely difficult decision to allow Nick to leave our club. As we have previously stated, Nick's move to North Melbourne would only occur through mutual agreement and as such, we have honoured a position that is beneficial to both him and St Kilda."
St Kilda coach Scott Watters also paid tribute to the midfielder.
“Nick has been a valuable part of St Kilda for a long time and will always be remembered fondly for his contribution to the club,” Watters said.
"While we are disappointed to let go of a person of Nick's calibre, he moves to a new team that presents a new opportunity to him and I would personally like to wish him well for his future.”
