The Flash (2014)

Going Rogue - S1-E4

Trivia: Kahndaq is mentioned heavily in this episode. Kahndaq is a fictional country, home to DC anti-hero, Black Adam.

Crisis on Earth-X, Part 3 - S4-E8

Trivia: Supergirl says to her doppelganger "General, can you step outside." That line was said by Superman in Superman II.

Attack on Gorilla City - S3-E13

Trivia: Julian asks Barry "are you gonna go to the planet of the apes?" Tom Felton played Dodge Landon in the modern remake of that film.

Attack on Gorilla City - S3-E13

Trivia: Before Barry and the others travel to gorilla city, Julian says something about Bludhaven. This is the city of Dick Grayson, aka Nightwing, former partner of Batman as the first Robin.

Trivia: Robbie Amell, who plays Caitlin's fiancee Ronnie, is the cousin of Stephen Amell, who plays the lead role on Arrow.

Fallout - S1-E14

Trivia: Towards the end when Caitlin and Iris are talking about her cousin they mention Midway. That's the city of Hawkman and Hawkgirl.

Fallout - S1-E14

Trivia: Towards the end Iris asks Caitlin about her cousin and they mention Coast City, the hometown of Hal Jordan, AKA Green Lantern, another DC superhero.

All Star Team Up - S1-E18

Trivia: When The Atom first appears, the characters say "It's a bird" "It's a plane", an obvious reference to Superman, played by Brandon Routh in "Superman Returns", who also plays The Atom in this episode.

Tricksters - S1-E17

Trivia: Mark Hamill plays James Jesse, the original Trickster, a role he also played twenty-five years earlier in the 1990 Flash TV series.

Cubs Fan

Luck Be a Lady - S4-E3

Trivia: Wally says he's going to move to Blue Valley. In the comics, Blue Valley is where Wally West (son of Rudy and Mary West) was from.

Invasion! - S3-E8

Trivia: The facility where the bunch of heroes are training is identical to the hall of justice from the 80's cartoon.

The Race of His Life - S2-E23

Trivia: The way the other Flash dies and vanishes is exactly how Flash did in the "Crisis on Infinite Earths" DC comic book.

Back to Normal - S2-E19

Trivia: The cellar where Wells was caught belongs to ACE chemical, a regular feature of DC comic book characters.

Welcome to Earth-2 - S2-E13

Trivia: When Barry, Cisco and Dr. Wells go to Earth 2, Supergirl and The Flash from the 90's TV show can be seen in the breach.

Running to Stand Still - S2-E9

Trivia: The drawings that the trickster has in his cell show the original image of the Flash in the comics.

Flash vs. Arrow - S1-E8

Trivia: The woman that knows Oliver is Sandra Hawke, mother of Connor Hawke, the second Green Arrow.

City of Heroes - S1-E1

Trivia: The Ferris air testing facility used by Barry to test his new powers features in Green Lantern comics.

Fast Enough - S1-E23

Trivia: While Barry is running through the wormhole we can see Caitlin as Killer Frost, the Flash museum and the Legends of Tomorrow.

The Man in the Yellow Suit - S1-E9

Trivia: Amanda Pays plays Dr. Tina McGee, head of Mercury Labs, a rival to S.T.A.R. Labs. She also played Tina McGee in the 1990 TV show The Flash, however in that series she's the one who helped Barry and built his special suit.

Trivia: John Wesley Shipp, who plays Henry Allen (Barry Allen's father), played Barry Allen in the 1990 TV show The Flash.