Slattery, 28, played 96 games for Essendon in the AFL after being drafted from West Adelaide with pick 46 in the 2004 National Draft and joined Port Adelaide as a SANFL player and welfare manager in 2013.
He played eight games after recovering from injury early in the 2013 before playing a further 13 games in the black-and-white guernsey as the club's SANFL vice-captain this year.
Preparing to focus on building a post-football career in the wine industry when he graduates in viticulture at the end of the year, Slattery said the time was right to step away from the League version of the game, but may pursue his options in amateur and country football.
“It’s been great here at Port Adelaide, I’ve had a great time in the last two years,” Slattery told portadelaidefc.com.au.
“I’m finishing my studies this year and have taken a job opportunity in the Barossa, so it’s now my priority to get my teeth into working in the wine industry.
“My wife and all my family have been very supportive and now we’re looking forward to the next chapter for us away from footy.”
Slattery thanked the staff who he worked closely with at Port Adelaide as a player in the past two seasons, particularly after the change from a traditional SANFL structure to a reduced 15-player senior list in the off-season.
“The SANFL is a great competition with a great standard that’s going to keep getting better, and I can’t keep up with the requirements of playing at this level," Slattery said.
“I’m a Port man for life now, it’s been a great experience to meet many great friends who I’ll have for ever. It’s a club full of passionate people and a strong culture.
“I want to thank all the club's support staff who stayed on with the change in structure and do a mountain of work for all the players in every grade.
"The coaches and admin staff continue to get us out on the park every week and you see the long hours they put in for the players, and of course the supporters continue to turn out more than ever to support this club."
Henry Slattery profile
DOB: 22 January 1986
Recruited from: Essendon/West Adelaide
SANFL League debut: Round 15, 2013
Career games: 21 Goals: 4
2014 games: 13 Goals: 3