Maginness (Pick 29 in 2019) signed a two-year contract extension to remain at Waverley Park until at least the end of 2023, whilst Howe - who is set to commence his eighth AFL season next year after being drafted to Hawthorn in 2014 - has furthered his stay by one year.
Howe, a Murray Bushrangers product, is coming off arguably his career-best season to-date in 2021, during which he averaged 18.7 disposals.
Hawthorn Head of Football Rob McCartney expressed his pleasure at being able to retain Howe, as he enters the prime years of his career.
"Now 26 years old and with 87 senior games worth of experience under his belt, [Howe] is starting to hit his prime," McCartney said.
"We saw this year, especially in the latter stages, that Dan really thrived and had some strong impact on games.
"So, we're hopeful of seeing him continue this kind of output into 2022."
As for Maginness, McCartney detailed the 20-year-old's maturation since entering the league.
"Finn has really applied himself to learning and understanding what it takes to be a professional footballer in the first two years of his career," McCartney said.
"His endurance capacity and work ethic are well-renowned, and we're really hopeful that he can continue to develop his game over the course of the next two years.
"It's exciting to be able to lock away a few of these youngsters as we continue to usher in this new era at Hawthorn."