Here is the full list of all 48 Persona 3 Reload achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Watched the good ending.
Sealed Nyx.
Maxed out all Social Links.
Unlocked all Social Links.
Fused Messiah.
Defeated the Reaper.
Awakened all teammates' ultimate Personas.
Invited Elizabeth to your room.
Defeated the Hanged Man.
Encountered a Dark Zone in Tartarus.
Earned over a total of 50,000 yen from part-time jobs.
Maxed out all Social Stats.
Defeated Fortune and Strength.
Discovered and conquered 10 Monad doors.
Nurtured a romance.
Defeated the Hermit.
Dealt over 999 damage in a single attack (All-Out Attacks excluded).
Used all teammates' Theurgy.
Defeated the Chariot and Justice.
Unlocked access to the remaining Major Arcana.
Initiated 50 Chance Encounters.
Accepted an invitation to hang out five times.
Maxed out one Social Stat.
Aced an exam.
Unlocked a teammate's Combat Characteristic.
Defeated the Hierophant and the Lovers.
Nursed a cat back to full health.
Maxed out one Social Link.
Obtained 10 Major Arcana during Shuffle Time.
Harvested a crop that you grew with a teammate.
Used a total of 50 Twilight Fragments.
Rescued a missing person.
Performed 50 All-Out Attacks.
Spent an evening in the dorm with a teammate.
Triggered a skill change during fusion.
Defeated the Empress and Emperor.
Obtained 10 Personas during Shuffle Time.
Performed a fusion with three or more Personas.
Obtained an item from a Persona Conception.
Opened 50 treasure chests.
Acquired every Twilight Fragment in town.
Ordered from a secret menu at the Iwatodai strip mall at night.
Defeated the Priestess.
Defeated a rare, golden enemy.
Performed a Dyad Fusion.
Performed a Shift.
Joined the Specialized Extracurricular Execution Squad.
Obtained Orpheus.