The one-cap Belgium forward signed on Friday for an undisclosed sum, penning a contract until 2019 with the Terriers retaining the option of another year.
Depoitre played in the Champions League while with Gent – where he won the Pro League – and during his undistinguished spell with Porto in the Primeira Liga.
Head coach David Wagner, who guided the Yorkshire club back to the top flight via the play-offs after a 45-year absence, was delighted to land his first target.
"I am very happy that we have made Laurent our first signing of this summer window," the German told the club's official website.
"He is a proper striker; one who has played for a very good Belgium side, featured in elite European competition and who has won domestic titles.
"It is great news that we have had the opportunity to sign a player of his quality and now we will focus on getting him back to the top form he showed only a season ago.
"He scores goals and is a real worker too, so he will fit the 'Terriers Identity' very well. His attitude on the pitch is exactly what we need, plus he is a very good character off the field too."
Huddersfield begin their maiden Premier League campaign away to Crystal Palace.