The character Shinra shares his name with the Shinra Electric Power Company in Final Fantasy VII. He also makes a resounding late-game statement which builds a strong case for Spira being the same world as the world of Final Fantasy VII.
When Rikku finds out about Zanarkand being turned into a tourist attraction by Cid, she compared it to "turning the ruins of Home into a theme park". Yuffie Kisaragi has a similar issue with Wutai being turned into "a cheesy resort town" by her father, Godo Kisaragi.
One of the Garment Grids, Healing Wind, is named after Aeris's initial Limit Break. In both appearances they are related to healing.
One of the Garment Grids, Salvation Promised, refers to the Promised Land.
Though Final Fantasy X-2 is set within the same world as Final Fantasy X, it contains many callbacks to that game. Numerous weapons are reused, such as Yuna wielding the Caladbolg while in the Dark Knight dressphere. Yuna also takes Tidus's battle pose and uses his victory dance when as Warrior. Additionally, the Celsius airship is a play off the airship name Fahrenheit in Final Fantasy X.
The three girls bear a stylistic resemblance to Charlie's Angels, especially in the first chapter of the game. This can be inferred from the flashy 70's style of their introduction.
During Chapter 5, when the player is given a description of the newly added Calm Landsminigames, they are told it is "Brought to you by Tobli, Calm Skies Partnership, and the letter Q". This is a reference to Sesame Street, a children's television show, which has a tradition "being brought to you by" a letter and number.
When the player visits Cactuar Nation for the first time and try to leave before finding out why Marnela called for the group, Picket, the probe guide, will tell the player to stay, and then will yell "No soup for you!" This is the catch phrase of the "Soup Nazi" episode from Seinfeld.
At the end of battle, Paine will say "Thank you". Rikku will add "Come again". This is the catch phrase of the Simpsons Quik-E Mart clerk Apu.
If the Prophet is nailed as the culprit in the Mi'ihen Highroad subquest of Rin's mystery, he'll spout the line: "And I would have gotten away with it too, if it weren't for you meddling kids!". He also says "Zoinks". This is an often used reference to Scooby-Doo. His voice sounds much like Shaggy's as well.
When spherechanging into the Gunner, Yuna might say "Resistance is futile". This is a reference to the Borg of Star Trek: The Next Generation.
During the sequence in Chapter 1 where the girls are sphere hunting in Zanarkand, Isaaru takes on the role of a game show host. If the player calls him out by having Yuna ask "Is that you, Isaaru?", he will ask "Is that your final answer?" which became a catchphrase of the hit ITV game show 'Who Wants to be a Millionaire?
Sometimes, while Rikku's casting a fire based spell, she will say "You're fired". This could be a reference to the show "The Apprentice" where contestants where eliminated by the same words.
If Paine casts Flare, she might comment, "You! It's what's for dinner!" This is a parody of an ad campaign by the American Beef Council which says "Beef, it's what's for dinner."
The file for Jumbo Cactuar at Shinra's Bestiary says the fiend is "Giant and green, but definitely not jolly." This is a reference to the Jolly Green Giant.
One of Rikku's quotes when casting Auto-Life is "Here's a quicker picker upper!" This a reference to Bounty paper towels, which has the slogan: "The quilted quicker picker upper."
One of Rikku's quotes when using the Gun Mage's Fiend Hunter bullet is "Let's do it! Al Bhed tested, Brother approved." This a reference to Kix breakfast cereal, which has the slogan: "Kid tested, mother approved."
One of the Gunner's abilities is called Quarter Pounder, which reduces the target's MP by a quarter. This is a reference to the McDonald's sandwich of the same name.
When spherechanging into the Black Mage, Yuna will sometimes quip "Double, double, toil and trouble." Rikku sometimes says "Fire burn and cauldron bubble." Both of these lines are said by the witches in the Shakespeare play Macbeth.
Rikku, Brother and others keep calling themselves the "Friendly Neighborhood Gullwings." This is an obvious reference to the old Spider-Man, who often called himself "just your Friendly Neighborhood Spider-Man".
In Chapter 5 if the player had slept in the cabin each chapter, Brother has a conversation with Barkeep about loving Yuna. Afterward, if the player goes down to the engine room, Buddy tells Yuna how he found the Celsius. The story he relates about being lost in a fog on a sea of ice only to be lead to the airship via a gull (a subsequent second gull appearing only to be shot and eaten), is very similar to the way a former captain recounts being led out of the Antarctic by an albatross (who is also shot and eaten) to a wedding guest in the poem The Rime of the Ancient Mariner by Samuel Taylor Coleridge.
At the beginning of the first battle with Yuna/Leblanc and her henchmen, Paine says "I could have danced all night." This is a line (and song title) from the musical My Fair Lady.
When Paine casts an ice-based spell, she'll sometimes say "Ice, ice baby." This is a reference to a briefly popular song by Vanilla Ice.
In Chapter 4, right before Yuna's concert in the Thunder Plains, Brother says "Spira is going to be killed softly by your song!" This could be a reference to the song "Killing Me Softly" by Roberta Flack, remade by The Fugees in 1996.
As the Gullwings are preparing for Yuna's concert in the Thunder Plains, Brother says "Achtung, baby. Let's clear the concert grounds." Achtung Baby is the name of a U2 album.
The first boss, Boris, is a reference to "Boris the Spider" by The Who. His "Sticky End" attack and his entry in Shinra's Bestiary reads "maybe he's as scared as you" are both references to lyrics in the song.
One of the abilities usable by the Sinistral Wing, one of the parts of Paine's special dressphere, Full Throttle, is named Ma'at's Feather after Maat, the ancient Egyptian concept of truth, balance, order, law, morality, and justice.