It's possible to skip Spoiler:Nyx Avatar, the final boss of the game. Spoiler:If you go to Paulownia Mall on January 31st and start the Social Link with President Tanaka (provided you gave him money at least twice beforehand), you'll automatically jump to March 3rd en route to the good ending.

If the protagonist has not entered Tartarus once within the first 10 days, upon returning to the Iwatodai Dormitory that evening, Mitsuru will confront and scold him/her for slacking off and forcibly bring him/her to Tartarus just before the first Full Moon Operation. She will also stop the protagonist from leaving until S.E.E.S has started exploring Block 1 of the tower.

In the "Answer" part of the game ending, Mitsuru can be heard saying the line "Is that it?". However, the game shows Akihiko and his portrait while the line is being said.

According to series character artist Soejima Shigenori, Aigis' "headphones" were designed to resemble the Antikythera mechanism, an analog computer made by the ancient Greeks to predict eclipses, as well as the locations of stars and zodiac constellations.

The character Chihiro Fushimi's design comes from an unused concept for S.E.E.S member Fuuka Yamagishi.

The intro song to Persona 3 FES is actually a remix of two different songs; The song "Memories of You" (the credits theme) and the song "Burn My Dread" (The main theme of Persona 3).

It was originally intended for Persona 3 Portable to include a "good" ending for the female protagonist involving Junpei confessing his love for her like the other male teammates. This was scrapped from the finalized version, however, the data remains in the game's data, including Junpei's Japanese voice files.

A set of early development videos show that there were plans for battles to be conducted through a fluid transition in the game's field, rather than in a designated battle area. Enemies would rise from the ground as a battle began, rather than causing a screen transition.

In the opening for Persona 3 FES, the protagonist, Junpei Iori, Yukari Takeba, and Akihiko Sanada are seen approaching the Full Moon Hermit boss. Spoiler:However, this isn't possible in the game, as Junpei Iori is captured by Chidori Yoshino before that mission, and could not be a part of your party for that fight.

Takaya Sakaki's gun is a Smith & Wesson Model 500, according to the Persona 3 concept art book.

According to Aram Jabbari, Assistant Manager of Public Relations and Sales, Persona 3's "M" rating in the United States is due to cultural differences between Japan and the USA.

Junpei's original victory pose alludes to John Travolta's disco pose from the movie "Saturday Night Fever".

During one of the anime cut scenes, Ken's red armband on his sleeve will disappear and reappear at the end of the scene.

Concept art shows that Ken originally used darts as a weapon, not spears as in the final game.

Koromaru is likely based off a real dog named Hachikou. Both dogs owners died, but the dogs go to the place they last saw their master, to wait for them to return.

While Cerberus is Koromaru's persona, a version of Cerberus can also be used by the game's Protagonist through the use of a cheat device.

In the PS2 update, Persona 3: FES, in the chapter "The Answer", all levels of the Abyss of Time get their names from Dante's "The Divine Comedy":
• The First Door, Malebolge, is the level where people who commit fraud are punished.
• The Second Door, Cocytus, is the lowest level of hell divided into for regions (the next four) where people who commit the sin of betrayal are punished.
• The Third Door, Caina, named after the Bible's Cain, is where people who betrayed family dwell.
• The Fourth Door, Antenora, named after Antenor from Homer's "The Iliad", is where people who betrayed their country dwell.
• The Fifth Door, Ptolomea, named after Ptolemy, governor of Jericho from the Bible who killed his guests, is where people who betrayed guests dwell.
• The Sixth Door, Judecca, named after Judas Iscariot also from the Bible, is where people who betray masters or benefactors dwell.
• The Seventh Door, Empyrean, is named after the the highest level of Heaven.

All the blocks' names in Tartarus, with the exception of the optional basement, Monad, are taken from the seven worlds of the Quabalah.

Cielo, the blue haired protagonist with dreadlocks from the Digital Devil series, has a soda named after him. Named Cielo Mist, it is described as being from Jamaica, giving reference to the American portrayal of him having a Jamaican accent.

There's a video game the protagonist receives called "Innocent Sin Online", a fictional MMORPG. Playing it will merit you the S. Link of the Hermit with a character who's screen name is "Maya". The name Maya is the name of one of the main characters in "Persona 2: Innocent Sin", as well as the protagonist in the follow up game "Persona 2: Eternal Punishment". The protagonist also has the screen name of "Tatsuya", referencing the protagonist of "Innocent Sin".