Fyfe, who did not feature for the Suns at AFL level, joined the Queensland club as a rookie via their Academy program in 2020.
The 19-year-old was recruited from Broadbeach as a rebounding defender that offered run and attack from the backline.
Gold Coast GM of player talent and strategy Craig Cameron expressed his thanks to Fyfe for his tenure with the Suns.
“On behalf of everyone at the SUNS I’d like to thank Aiden for his contributions to the SUNS and we wish him all the best for the future,” Cameron said.
Lemmens has inked a new three-year extension that will keep him in the red and gold until the end of the 2024 season, while Day has extended until 2023.
“It was really important that we were able to re-sign Sam and Sean as we see both of them as key members of our team over the coming years," Cameron said.
“Sean had his best season yet in SUNS colours and has developed into a highly-respected Indigenous leader at the club.
“While Sam had an interrupted year with injury, he still has a lot of high-quality football in front of him and we see him as an experienced key pillar in our forward line structure.”