The Scottish side have been tracking the Stromsgodset midfielder as they weigh up a move during this month's transfer window.
Lennon has admitted Celtic have made an enquiry for Johansen and could table a bid for the 23-year-old later this week as they look to steal a march on their rivals for his signature.
"There is an interest and we have made an enquiry for him but I don't know how far down the line we are with it," Lennon told the Daily Record.
"He's a good young player we've had watched a couple of times."
Asked if a bid for Johansen was imminent, Lennon added: "Maybe this week. We are hoping that's just one of a few irons in the fire."