#3 Thomas Lemar - €72 million
The third-most-expensive sale in Monaco's history is of the 26-year-old midfielder. Thomas Lemar was part of Caen's youth system and he made his professional debut for them in 2013. The Frenchman helped his side get promoted to Ligue 1 in his second season, after which Monaco signed him for a fee of €4 million.
He immediately became an important part of the Monaco side and he even appeared 55 times in a season. He could play any position ranging from midfield to wing and his versatility grabbed attention from big clubs in 2017.
Premier League giants Arsenal and Liverpool's initial bids were turned down by the club. Arsenal, however, made an enormous second bid of €100 million, but the player was disinterested in a move to the Emirates Stadium.
In 2018, Atletico Madrid confirmed his signing from Monaco for a fee of €72 million. Notably, he won the La Liga title with the Spanish club last season.
#2 James Rodriguez - €75 million
James Rodriguez was one of the most expensive transfers for both Monaco and Real Madrid. Rodriguez became Colombia's youngest professional debutant in club football when he started for Envigado at the age of 14.
Moving to Argentina in 2008, he became a famous personality while playing for Banfield. Still a teenager, he scored a goal that made pundits liken him to the playing style of Cristiano Ronaldo.
He started getting attention from Europe and joined FC Porto in 2010. His progress rate kept rising and in 2013, Monaco made him their most expensive arrival.
A brilliant season there and an important 2014 World Cup display was enough for his dream to come true. The following year after Monaco signed him, Real Madrid completed his transfer for €75 million, making him one of the club's most expensive arrivals. He is currently playing for Al-Rayyan after his Everton spell ended in disappointment.
#1 Kylian Mbappe - €145 million
A player tipped to be the next big thing after Lionel Messi and Cristiano Ronaldo, Kylian Mbappe is extremely talented and started off his football journey with Monaco. He made his professional debut for them in 2015 and has gone on to break many individual records.
However, it was the 2016-17 season that saw a breakthrough for the phenomenon. The same season, Monaco reached the quarter-finals of the Champions League and also dethroned PSG for the Ligue 1 title. He quickly became a target for PSG and initially joined them on a loan deal.
It took a little bit of convincing as he was a Real Madrid fan and a huge admirer of Zinedine Zidane. However, he wouldn't get a regular spot there because of which he agreed to join PSG.
The French side then splashed €145 million to sign him from Monaco, making him the most expensive teenager and the second most expensive player in the world.