The club first broke their record this summer with the £10 million signing of midfielder Aaron Mooy from Manchester City, while former Derby County striker Tom Ince followed for an undisclosed fee that overshadowed the sum paid for the Australian.
Mounie, 22, has signed a four-year deal with Huddersfield for a reported fee of more than £11m just a day after they announced the signing of US international Danny Williams on a free transfer.
A Benin international, who stands at 6'3”, Mounie recorded a goal return of 14 strikes in 32 starts in his first full season in Ligue 1.
Terriers coach David Wagner has been hard at work bolstering his squad for the challenge of Premier League survival and has hailed his latest signing's physical attributes ahead of what is sure to be a tough season for the top-flight newcomers.
“I’m delighted that we could sign Steve ahead of the start of pre-season training,” Wagner told Huddersfield's official website.
“He has a very exciting combination of attributes that makes him a very attractive proposition as a young striker.
“He has real physical attributes that should be perfect for the Premier League, plus we have already seen his talents as a footballer in his remarkable season in France.
“We have met and I know he is a great character. For a man of his young age, he already has great experience both in life and as a footballer from his time in France, playing in a high-quality Ligue 1.
“At just 22 years old, he is only going to improve too. Given what he is already capable of, that is very exciting.”
Huddersfield's first clash of the Premier League season sees them take on Crystal Palace at Selhurst Park.