Song had spent the final three years of his playing career with AS Arta/Solar7 in Djibouti, collecting two Djibouti Premier League titles and two Djibouti Cups, but he only played five times for the club following his arrival in November 2020.
The 36-year-old's most recent appearance for AS Arta/Solar7 came in the first round of last year's CAF Champions League, playing the full 90 in a goalless draw with Al-Merrikh SC in September 2022.
Having not been seen on the pitch since, Song - who also helped oversee the development of youth players with the African club - has hung up his boots following a 19-year stint as a senior player.
"It is with great sadness that the time has come for me to hang up my boots," Song wrote on Instagram. "My journey that began in Yaoundé as a child, playing with no boots, in bare feet and on hard gravel, gave me the strength and courage to succeed.
"When I moved to France, playing for Bastia I thought I had achieved a miracle. However, this was only the start as my journey continued to Arsenal and Barcelona, two of the greatest clubs in the World. So many people have helped me along the way, my wife, my kids, family, friends, my agent, coaches and of course all my teammates whom I will forever be grateful.
"Of course Charlton, West Ham, Rubin Kazan, Sion and Arta/Solar 7 will always remain in my heart. Having the honour of representing my country 60 times also filled me with great pride. I feel blessed with so many great memories that will remain with me forever.
"Lastly, I would like to thank all the fans who have supported me along the way, I will treasure everything. I hope to see you all again soon. Alex. There is only one Song."
Song plied his trade in the Bastia academy before transferring to Arsenal for €4m (£3.5m) in 2005, and after making fleeting appearances for the Gunners, the Cameroonian spent the second half of the 2006-07 season on loan at Charlton Athletic.
Over the next five years, Song developed into an integral player for Arsenal under Arsene Wenger, scoring 10 goals and providing 23 assists in 204 games for the club, setting up 11 goals in the 2011-12 top-flight season as he formed a strong on-field bond with Robin van Persie.
Song's exploits in his final season at Arsenal saw him finish third in the vote for the 2012 African Footballer of the Year behind Didier Drogba and Yaya Toure, and he was sold to Barcelona for €19m (£16.5m) that same summer.
The midfielder scored one goal and set up two more in 65 games for Barcelona, winning one La Liga title and one Supercopa de Espana, but he failed to hold a regular starting spot in the Blaugrana's star-studded engine room.
Song subsequently returned to the Premier League with West Ham United on a two-year loan deal, playing 46 times for the Irons before joining Rubin Kazan on a free transfer in 2016 when his Camp Nou deal expired.
Following an underwhelming period in Russia, Song was on the books with Swiss outfit Sion for a year and a half, departing the club in March 2020 before returning to Africa.
During his international career, Song provided four assists in 47 games for Cameroon, representing his country at two World Cups and two Africa Cup of Nations, earning a spot in the Best XI for the latter tournament in 2008 and 2010.