Artwork from the "Fossil Excavator" card appears in the art museum of Lumiose city.

The artwork of a Pokemon trading card, "Town Volunteers", makes an appearance in The Lumiose Museum.

In Coumarine City there is an Ace Trainer in a house that will play a remastered version of "Unwavering Emotion", a song from Pokemon Black and White's soundtrack.

A young Professor Sycamore wrote a note to his future self, and left it in Couriway Town. It can be found and read by examining the left side of the right bench in the station there.

A woman in Snowbelle City states, "Standing here reminds me of a cold region far away. Will you listen to the first song I composed there?" Answering yes will play a slowed-down version of the theme of Jubilife City, from the Sinnoh region of Pokemon: Diamond & Pearl, which slowly picks up in tempo.

In Lumiose City Station, if you interact with the back of the TMV Timetable closest to the wall, it will read: 'Something is written on the back of the timetable. "I'm going to go for help. Wait in the usual place."' There is also a child standing nearby who says "It should be some place right around here, right?" People believe this child is looking for the 'usual place.'

If the player visits a Pokémon Center on their birthday in any of the Generation VI Pokémon games, they will receive a special message wishing them a happy birthday.

In the Japanese versions, the Pokémon Center will additionally play a music box rendition of "Happy Birthday to You", which is replaced by a similar version of the Pokémon Center theme on subsequent visits that day. The international release omits the former song, only playing the latter even on the player's first visit. This is owed to the fact that "Happy Birthday to You" was still nominally under copyright in the United States, not officially falling into the public domain until 2016 after a three-year legal battle (the song was declared de facto public domain in 2015, but the final settlement was not issued until the following year).

On the second floor of the building to the right of the Galette stand in Luminose City, immediately after entering the floor, the lights will flicker on and off and a Hex Maniac will appear behind the player, who will then float (as she seems to lack any kind of walk animation) off screen and say, "No, you're not the one..." before disappearing.

In the first room on the right on the fourth floor of the Hotel Richissime, she will be there as well. When talking to her, she will say, "Don't talk to me... if you do, I can't hear the elevator..."

There has yet to be any explanation as to who this character is.

An NPC in the Shalour City Pokemon Center will describe a game to the player, which references another Game Freak title, HarmoKnight.

Veteran Timeo references the E3 2007 Wii Fit demonstration by saying "my body is ready!", a phrase said during the demonstration by Nintendo of America president Reggie Fils-Aime.

Junichi Masuda has stated that the name "Kalos" derives from the Greek word "καλός", meaning "beauty".

Pikachu's cry was changed to match how it sounds in the Pokemon anime. Pikachu's cry was also changed this way in Pokemon Yellow, and it was possible to unlock the anime call in Pokemon Stadium.

A trainer in the game makes a reference to the popular "It's over 9000" Dragon Ball Z meme.

In Pokémon X and Y, Gamefreak gave a proper name to every attack that was mistranslated in the original Spanish Red and Blue versions. The changes are:

-Slam will be named Atizar instead of Portazo (Door Slam).
-Constrict will be named Constricción instead of Repetición (Restriction).
-Counter will be named Contraataque instead of Contador (Counter from the verb "to count").
-Return will be named Retribución instead of Retroceso (Return as in "Return somewhere")

Pokemon X and Y are the first Pokemon games to let you select any of 7 different languages.

This is the first main series Pokemon game to have a worldwide same-day release, rather than releasing in Japan first.

The game's region (Kalos) is based on France.

In the 2nd UK Pokémon X and Y trailer, while Yveltal is using a Hyper Beam, you hear the sound effects for Pokemon Red & Blue's Hyper Beam.

The reason Fairy type Pokemon were introduced was to balance out the game. Fairy type has an advantage over Dragon type, which was considered an overpowered type by Game Freak.

In the game's reveal trailer, when the male character swings on the vines, his glasses don't follow him.