Sessegnon enjoyed a superb season as Fulham clinched promotion to the Premier League in 2017-18, making 48 Championship appearances and scoring 16 goals for Slavisa Jokanovic's side, along with featuring in their play-off final victory against Aston Villa.
The 18-year-old has been linked with a transfer to Tottenham during the current transfer window but Khan, who is also co-owner of the Jacksonville Jaguars NFL team, posted a message on his Twitter account to refute suggestions that Sessegnon might be allowed to leave Craven Cottage in the imminent future.
"We're not selling Ryan Sessegnon," said Khan. "We've never considered it!
"I couldn't sit back and read these false rumours anymore, had to say something.
"Ryan's key to this Fulham squad; he's one of the top young talents worldwide and in our plans for Premier League success."
Sessegnon, who joined Fulham as a junior, has risen through the club’s academy system to become one of their standout performers, with Bayern Munich and Manchester United among those linked with him before he committed his future to the Cottagers in 2017 with his first professional contract.
He won three individual honours at this year’s EFL Awards, including Championship Player of the Year and EFL Young Player of the Year, as well as featuring in the Team of the Year.
At international level, Sessegnon has represented England at four separate youth levels and was a member of the U19 team who won the European Championship in Georgia in 2017.
The Cottagers have enjoyed a moderately busy transfer window, capturing Serbian forward Aleksandar Mitrovic from Newcastle following a loan spell and adding defender Alfie Mawson from relegated Swansea City.