Reid wants to take the former Lens forward on loan for the season with a view to a permanent deal.
The 25-year-old Senegal international played for The Whites during the recent Dublin tournament and despite his side's dismal performance Reid was impressed by the trialist.
He linked up well with Alan Smith in the 2-2 draw with Villa and also showed some nice touches against Shelbourne.
"He looked as if though he can handle the ball well, has pace, has got a spring about him and he surprised me with his athleticism," he told the club's official website.
"At times he looked a threat for us and he impressed me, I have to say that.
"I think he can go left or right as well and it helps if you have got that options. I've seen him in video's as well and I like what I see."
His agent Willie McKay has stated that the African is thrilled at the prospects of moving to Elland Road, and said: "Sakho has impressed Peter Reid and he is keen to sign him. He is signing on a one-year loan with the option to buy him at the end of it for £3m.
"He was great in Dublin for Leeds and their fans gave him a standing ovation after one of the games. He is looking forward to the chance of playing in England as he thinks The Premiership will suit him.
At Marseille he was played out of position and he is keen to get his career back on track.
"He is excited at the chance of playing with Alan Smith as he thinks he is a different class," added McKay. "He believes that Leeds can have a good season as there is still a lot of great players at the club."
The Leeds boss currently only has three senior strikers at Elland Road, the injury-prone Michael Bridges, want-away Mark Viduka and Alan Smith.