The former Celtic and Bolton Wanderers head coach has committed to the Easter Road club until 2020.
Lennon took the Hibs reins in June 2016 and went on to win the Scottish Championship title in his first season, and following their return to the top flight, they sit sixth in the Scottish Premiership table after four matches.
The 46-year-old told Hibs' official website: "I am delighted to have signed the deal. I've made no secret of my enjoyment of my time at Easter Road and my desire to stay on at Hibernian.
"All of the parts are in place to build a strong future. We have a strong group of players, we are seeing talented youngsters like Fraser Murray and Ryan Porteous force their way into first-team contention, and we have good, supportive people running the club.
"The infrastructure is first class, it's a great club, and now I want to do all I can to make it a successful one."
Lennon also took Hibs to the semi-finals in the Edinburgh club's defence of the Scottish Cup last term and has a League Cup quarter-final with Livingston to look forward to this month.