Only 16 at the time, the forward came in the 88th minute of a 1-1 home draw with Caen, becoming Monaco's youngest player in history, breaking the record previously held by Thierry Henry.
Eight major club trophies (and a Trophee des Champions), a World Cup winners' medal and a reported €180million transfer to Paris Saint-Germain have followed since for a player already considered one of the greatest in the world even before his 22nd birthday later this month.
He can also make history on Wednesday if he finds the net in a key Champions League match for PSG against Manchester United...
COMPARED TO FRANCE...
Mbappe has established himself as one of the most lethal strikers in Ligue 1 since his Monaco debut five years ago.
In 125 appearances in France's top flight, he has scored 89 goals and provided 33 assists, giving him at least seven more direct goal involvements than any other player in that time at an average of almost exactly one per match.
Since December 2, 2015, only former PSG team-mate Edinson Cavani (96) has scored more goals in Ligue 1 than Mbappe, while only Angel Di Maria (54) and Memphis Depay (36) have more assists.
Mbappe has managed 212 shots on target in his Ligue 1 career, at least 32 more than any other player in that time, while he sits third for attempted shots overall on 383 (behind Di Maria on 400 and Andy Delort on 414).
The 21-year-old has attempted 562 dribbles, a tally bettered only by Neymar (594), Florian Thauvin (622) and Allan Saint-Maximin (696). He is fifth for successful dribbles, his 272 behind those three players and Hatem Ben Arfa.
COMPARED TO EUROPE...
Across Europe's 'top five' leagues, Mbappe is 14th for goals since his Ligue 1 debut.
Only eight players have scored more than 100 league goals in that time, with Lionel Messi top on 158, ahead of Robert Lewandowski (143) and Cristiano Ronaldo (137).
For combined goals and assists, Mbappe (122) is ninth among Europe's elite, six short of eighth-placed Pierre-Emerick Aubameyang (128). Again, Messi is top by a distance (227), above Luis Suarez (177) and Ronaldo (171).
KYLIAN IN THE NAME OF
Mbappe made history in February 2019 when, against Nimes, he became the youngest player to reach 50 Ligue 1 goals in the past 70 seasons (at the age of 20 years, two months and three days).
In that 2018-19 season, Mbappe scored 33 league goals, becoming the top-scoring French player for PSG in a single campaign and the leading French goalscorer in a Ligue 1 season in the 21st century.
Last October, Mbappe broke Messi's record to become the youngest player to score 15 Champions League goals at the age of 20 years and 306 days. Erling Haaland has since achieved the feat at a younger age.
If he scores against United at Old Trafford, Mbappe will reach 100 goals for PSG in all competitions. It will also be his first goal in the tournament in 2020.