The defender has shone at Elland Road since arriving in the summer on a season-long deal.
And the 25-year-old has now committed his long-term future to the Championship club.
Jansson has agreed a permanent switch for the summer where he will begin his three-year deal.
"Yes [I knew that I wanted to be at this club for many years], actually from the first day," Jansson told the club's official website.
Pontus Jansson has impressed for Leeds since arriving on loan in the summer
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I had a good feeling when I came here
"I had a good feeling when I came here."
On when he signed on loan last summer, Jansson continued: "Garry [Monk] remembered me from when he was at Swansea and I was at Malmo and we played against them.
"[I remember] the feeling when I saw Gary for the first time when I came to Elland Road. He came over and gave me a big smile and big hug. That was so important for me. In Italy the situation with the coach is a little different."
Jansson, who has demonstrated his emotion on the pitch, has struck up a close bond with the Leeds fans since his arrival at the club.
He added: "I play with a lot of emotion, a lot of feelings. Maybe they see themselves in me on the pitch.
"I am really thankful for it. Every time I go out on the pitch I have a big smile on my mouth because I know they love me. It's easy for me to play like that."
Janssen's focus is now on trying to secure promotion back to the Premier League with fourth-placed Leeds.
They sit five points off automatic promotion and were boosted in their pursuit of Brighton following their 3-1 defeat at Huddersfield tonight.