The 28-year-old player was without a team since parting company with Belgian football club KV Oostende in August.
Rezaeian had to find a new club because he is going to be a member of Team Melli in the upcoming 2019 AFC Asian Cup in the UAE.
Al-Shahania sits 8th in 12-team Qatar Stars League, 16 points behind leader Al-Duhail.
Rezaeian started his playing career in Saba in 2009 and has also played in Iranian clubs Rah Ahan and Persepolis.
He is third Iranian player who plays in Qatari clubs.
Omid Ebrahimi and Mohammad Reza Khanzadeh are playing at Al Ahli.