The former Huddersfield and Birmingham manager will need to hit the ground running at Rugby Park, with the team just one point above the relegation play-off place.
And his old team-mate Alex Rae - the St Mirren manager - reckons the Killie board have chosen wisely.
"I think he will be a very good addition to Scottish football," Rae told BBC Scotland.
"I knew him from playing against him, and he became a team-mate in 1997 when he joined Sunderland.
"Lee has been around a long, long time now as a player and in the coaching and management side of things."
Kilmarnock can certainly expect to see a manager who wears his heart on his sleeve.
"The one thing about Lee Clark is you definitely see his passion, you see him running up and down the touchline," added Rae.
"The board will be looking for a little bit of a bounce, they will be hoping they can continue the form from the last couple of games where they have drawn with Rangers and got a really good result at the weekend [a 2-0 victory at Motherwell]."
"He will be going into a dressing room that will be a wee bit encouraged."
The undoubted highlight of Clark's managerial story thus far was his first job. It ran from 2008 to 2012 following coaching spells at Newcastle United and Norwich City.
For a while he was a huge prospect down south, famously taking League One Huddersfield on a 43-match unbeaten run.
Backed by chairman Dean Hoyle, the remit for Clark was to take The Terriers into the Championship. Twice they made the play-offs. Twice they failed to go up.
Eventually patience ran out and in February 2012 Clark was sacked following a 1-0 defeat to Sheffield United - a decision that looked harsh considering Clark had only lost three of his previous 55 league matches to that point.
Hoyle wanted promotion and got it, with Clark's replacement, Simon Grayson, delivering via the play-offs.
One of Clark's last signings for Huddersfield was Kallum Higginbotham - a player he will be reunited with at Kilmarnock.
Clark would graduate to the Championship with Birmingham City but it was a time of turmoil at the club.
Twice he preserved their status in the division, albeit survival in the 2013-14 season was secured by the tightest of margins - an injury-time goal from former Celtic player Paul Caddis keeping them up on goal difference.
But a poor start to the following season saw Clark sacked in October 2014.
His last managerial stint was an unhappy one as he immediately moved to Blackpool, who were bottom of the Championship. Relegation followed and he resigned in May 2015.
Rae thinks it would be wrong to read too much into this dismal spell at the Seasiders.
"The one thing about working for Blackpool - I was there as well - it is a really tough, tough environment to work in," he said.
"The downsizing in terms of the playing budget almost made it impossible to succeed there. I would not judge Lee on that last tenure."
The Killie board clearly like what they see in Clark but he is entering an environment he has little experience of.
The 43-year-old is joining a club where money is tight and this will present challenges. He will need to be resourceful to make changes.
There is precious little breathing space at the foot of the Premiership and the stakes are high for a club that could certainly do without enduring the financial hardship relegation would bring.
'Big prospect' is a tag that has hung around Clark both as player and boss. That is no longer the case and there is a sense of unrealised potential.
But there is clearly a hunger to succeed as well. Kilmarnock may not be a final throw of the dice for Clark but there are only so many chances for managers in a highly competitive marketplace.
As a youngster Clark was an exciting talent with the club he loved, Newcastle United. He represented England at schoolboy and at under-21 level.
He enjoyed a very successful career - twice finishing as a Premier League runner-up with the Magpies and also played in the top flight with Fulham.
Lee McCulloch and Peter Leven are staying on as Killie coaches and Rae thinks Clark will rely heavily on his new Scottish lieutenants.
"These boys know the personnel and also the division," explained Rae.
"The one thing about Lee is he is a motivator. He gets his teams at it. I have played against his Huddersfield - excellent back in the day. He will bring a lot to the table."
Lee Clark is a name well known to fans in England but the new Kilmarnock boss is less familiar in Scotland.