The Sweden international becomes signing number 10 for Garry Monk's Whites.
New Leeds United signing Pontus Jansson has posted messages to both the Whites and parent club Torino on Twitter.
The Sweden international became Leeds' 10th summer signing on Thursday, arriving on an initial season-long loan deal.
Torino later confirmed in a statement on their official website that the deal includes an option to buy Jansson outright and the defender's message to the Italian side appears to signal the end of his time at the Stadio Olimpico.
"I would first like to thank all the players and managers for these two years," the 25-year-old posted via his Twitter account.
"Competition in my position was tough, but every time I had the chance I was always positive and did everything possible for Torino.
"Thanks to all the fans for all the support and I'm sorry this is the end."
Shortly after, Jansson switched focus to the future, tweeting: "Let's do this! I'm so happy to be here and now I will give everything for this shirt."
Lets do this! Im so happy to be here and now i will give everything for this shirt. pic.twitter.com/p368tQiNfl— Pontus Jansson (@PJansson5) 18 August 2016
Jansson, who reunites with former Malmo assistant Pep Clotet at Leeds, signed for Torino in 2014 on a free transfer.
The 6ft 5 centre-back only made 25 appearances in that time, six of which came in the 2014-15 Europa League, but was named in Sweden's squad for this summer's European Championship nonetheless.
Jansson, will compete with Sol Bamba, Kyle Bartley and Liam Cooper at Elland Road, is currently awaiting international clearance ahead of Saturday's Yorkshire derby with Sheffield Wednesday at Hillsborough, according to the YEP.