Sessegnon rose through the youth ranks at Fulham before going on to make 120 appearances for the first, contributing 25 goals and 18 assists.
The 24-year-old left the Cottagers in the summer of 2019 to move across London to Tottenham in a reported £25m deal.
Unfortunately for Sessegnon, he saw his time with Spurs disrupted by a series of injuries, restricting him to just 57 appearances in all competition.
Sessegnon was released by Tottenham earlier this summer after playing just seven minutes of first-team football last season.
Fulham announce first summer signing
Despite Sessegnon's recent injury struggles, Fulham have decided to sign their academy graduate on a free transfer, making him the club's first signing of the summer transfer window.
The left-sided player has put pen to paper on a two-year contract, with the option to extend by a further 12 months.
"It's amazing to be back," Sessegnon told FFCtv. "Emotional, as well. It's where it started for me, where everything began, and it's amazing to be back.
"It will always be home for me. I think it had the feeling that it was meant to be, coming back here, so I'm delighted to get it done."
Fulham "thrilled" to re-sign Sessegnon
Fulham vice-chairman Tony Khan has admitted he his delighted to bring Sessegnon back to the club for a second spell.
"I'm thrilled to announce that Ryan Sessegnon has returned to Fulham Football Club!" Khan said. "Ryan grew up in our academy, he spent 11 years at the club, as he developed here into a wonderful young man and a phenomenal talent.
"I remember travelling to Leeds for the first league start of his career on 16/8/16 as if it was yesterday. We're all so pleased that Ryan has come back, he is beloved here at the club by our staff and supporters, and we know that he'll be right at home, working with old friends and new, under Marco Silva's great leadership. Welcome home, Sess!"
The former England Under-21 international could prove to be a shrewd addition if he can prove his fitness for an extended period.
Sessegnon can play anywhere on the left flank, providing Silva with the option to play him as a full-back or in more advanced areas.