The 22-year-old Frenchman has been highly sought after by Premier League clubs in recent times, with Newcastle United, Manchester United and Arsenal rumoured to have had an interest in Soumare previously, however, the Foxes moved first, with the first signs of a deal being completed back in February, when transfer expert Fabrizio Romano confirmed of Leicester's intentions.
Fresh off the back of an unlikely title win in France, Lille have encountered financial troubles off the pitch, meaning many of their start assets are likely to be sold on in the summer, with Soumare the first of several high-profile departures.
With just one year left on his contract, it is estimated that he will cost Leicester a fee in the region of £20m as Brendan Rodgers looks to further strengthen his squad.
Why have Leicester signed Soumare?
Quite simply, Leicester need more quality in depth in the middle of the park, and the former Paris Saint-Germain academy graduate offers that in abundance.
Whilst Leicester have talents in Nampalys Mendy, Dennis Praet and the returning Kiernan Dewsbury-Hall to call upon as back-up to their usual starters of Wilfred Ndidi and Youri Tielemans, there's no question that Soumare on paper is an upgrade on all of them.
Furthermore, Rodgers has also expressed his desire to bring in at least one or two signings with a 'winning mentality' - proven by his ability to be a part of a side to topple PSG to the top-flight title in France.
Leicester will also have ambitions of going deep into the Europa League this season as well as take the one final step needed to finish in the top four - something they have failed to achieve in back-to-back seasons now.
In order to compete with the best, you have to constantly improve and if Leicester want to continue to establish themselves amongst the big-guns in the league, signings like Soumare will do no harm in helping them.
What will Soumare offer to Leicester?
In terms of style of play, Soumare offers a blend of what both Ndidi and Tielemans bring to the Foxes.
Normally operating on the left-hand side of a two-man pivot, the youngster has the perfect blend of physicality and technicality. Standing at 188cm tall and well-built, Soumare can challenge for any aerial duel whilst also posing a threat from set pieces in the opposition box.
Soumare is also technically very gifted. He can comfortably use both feet and is an excellent carrier of the ball, allowing him to accelerate and break through defensive lines and spot a pass, showcased by his average pass success rate of 89% last season.
While he won't offer goals, scoring just once in his career, he enables the more creative players in the ranks to play their game, covering for them if need be or joining to provide an extra attacking number.
With another congested fixture list coming up for Leicester this season, Soumare will provide the perfect opportunity for the Foxes to take the burden off Ndidi and Tielemans without severely weakening the middle of the park.
There may even also be scope for all three to play together but rest assured, the signing of Soumare would be very astute business from Leicester and one that many of their rivals may look at in the future as a missed opportunity.