This is a chronological list of significant events in the anime and the episodes which they occurred in, or, for events which happened outside the series, where they happened in relation to the episodes.
| Time || Details |
|The beginning of time |
- Arceus appears in the darkness in the form of an Egg. After hatching, it creates the universe. (M12)
|4,600,000,000 years prior |
|2,000,000 years prior |
- First Pokémon, as dated by archaeology. (EP163)
- The Meteonite enters Earth's atmosphere and breaks up with the largest fragment impacting into the landmass that would become the Unova region. (BW009)
|2,000 years prior |
|1,000 years prior |
|500 years prior |
|400 years prior |
- Azalea Town experiences a devastating drought that ends when a Slowpoke's yawn brings rain, prompting the town's people to begin a time-honored tradition of respect for all Slowpoke. (EP142)
|300 years prior |
- The Orange League takes place for the first time. (EP095)
- The captain wins the Orange League.
- The captain's ship gets caught in a storm and sinks.
|200 years prior |
- Early versions of Poké Balls are used. (EP232)
- Lokoko's master, who looks identical to Brock, leaves his home in Johto to go on a journey. His Ninetales is left waiting for his return at his mansion. He never returns. (EP232)
|100 years prior |
- Lokoko's master's Ninetales realizes that its master must be dead by now and tries to leave his mansion, but is unable to, as its Poké Ball remains there. (EP232)
|100 years prior to XY |
|55 years prior to SM |
|50 years prior |
- Samuel Oak is born. (M04)
- Lokoko's master's Ninetales discovers that it has developed mysterious powers. (EP232)
|40 years prior |
|30 years prior |
- Kaiser reports the existence of a Dratini in the Safari Zone. Thousands of people come there to try catching the rare Pokémon, literally destroying the Safari Zone in the process. Since then, only Safari Balls are allowed to be used there. (EP035)
|29 years prior |
|20 years prior to BW |
|20 years prior to SM |
|15 years prior |
|15 years prior to BW |
|11 years prior to DP |
|10 years prior |
|10 years prior to AG |
|10 years prior to DP |
|10 years prior to BW |
|10 years prior to XY |
|10 years prior to NS |
|7 years prior to AG |
|Less than 10 years prior to XY |
|5 years prior |
|4 years prior to SM |
- Lillie is nearly abducted by a Nihilego, but she is rescued by a Silvally. The traumatic experience makes her afraid of touching Pokémon. (SM049)
|4 years prior to NS |
- Go and Koharu attend a Pokémon Summer Camp hosted by Professor Oak. Ash also signs up for the camp too, but he woke up late, missing his opportunity to go there. (SS001)
- Go and Koharu encounter Mew, leading to Go's dream of catching Mew once he became a Trainer. (SS001)
- Pikachu is born as a Pichu and raised by a Kangaskhan until its evolution and departure. (SS001)
- Pikachu is caught and eventually transferred to Professor Oak's Laboratory. (SS001)
- Meowth meets Meowzie. (EP070)
- Meowth learns to talk and walk on two legs. (EP070)
- Meowth is rejected by Meowzie and joins Team Rocket. (EP070)
- Jessie and James join Team Rocket. (HS12)
- Jessie receives an Ekans as a chūgen present (birthday present in the dub). (EP017)
- James receives a Koffing as an oseibo present (Christmas present in the dub). (EP017)
- Brock catches a Geodude.
- Flint leaves Pewter City to train, leaving the Pewter Gym in the hands of his oldest son, Brock. (EP005)
- Lola leaves Pewter City out of boredom, leaving her children in the hands of her oldest son, Brock. (EP005)
- In the dub of EP005, Flint says Lola died at this point, rather than leaving. In subsequent episodes where Lola appears, the dub follows the original with Lola leaving home and leaving everything in Brock's care.
- Misty catches Goldeen, Staryu, and Starmie.
- Tracey catches Venonat and Marill.
- Iris catches a Drilbur, which later evolves into Excadrill and starts disobeying her. (BW033)
- Misty leaves Cerulean City to train, leaving the Cerulean Gym in the hands of Daisy, Lily, and Violet. (EP007)
- Serena is sent to Pallet Town in Kanto against her will, to attend a summer camp hosted by Professor Oak. She gets lost in a nearby forest, and hurts her knee, where she meets Ash and is rescued and led back to the camp by him. (XY007)
- Clemont befriends a Shinx when studying in an academy specializing in Electric-type Pokémon. It later evolves into a Luxio. (XY048)
- Mallow's mother catches a Bounsweet and gives it to her daughter. (SM108)
- Mallow's mother passes away due to an illness. (SM108)
- Lana and Mallow meet each other for the first time. (SM059)
- Zoey finds a Glameow in an alleyway of Snowpoint City and raises it with Candice. (DP126)
- Cilan, Chili, and Cress become Gym Leaders of the Striaton Gym. They catch their Pansage, Pansear, and Panpour, respectively.
- Cilan becomes a licensed A-Class Pokémon Connoisseur.
- Clemont becomes Gym Leader of the Lumiose Gym. He catches his Magnemite, Magneton, and Helioptile, which he later evolves into a Heliolisk.
- Iris receives a newly hatched Axew from the elder of the Village of Dragons. (BW009)
- Alain leaves Sycamore Pokémon Lab, allies with Lysandre, and achieves Mega Evolution with his Charizard. (XYS01 & XYS02)
- Mairin starts her Pokémon journey with Chespin, nicknamed Chespie. (XYS01)
- Kiawe completes Olivia's grand trial, and receives a Z-Ring and Charizard from his grandfather. (SM002, SM011)
- Ash wins a Pokémon League Expo hat. (EP025)
|1 year prior to DP |
|Less than 1 year prior |
- Ash and Gary find an old Poké Ball while fishing, breaking it in half after arguing who will get it. Each of them keeps one of the pieces as a symbol of their rivalry. (EP269)
|Less than 1 year prior to DP |
|Less than 1 year prior to XY |
|Less than 1 year prior to SM |
| Episode || Details |
|Pokémon, I Choose You!|
|Ash Catches a Pokémon!|
|Challenge of the Samurai|
|Showdown in Pewter City|
- Ash and Misty reach Pewter City
- Ash learns about the Pokémon League, Gym Leaders, and Gym Badges.
- Ash and Misty meet Brock, the Pewter Gym Leader, and his father, Flint.
- Ash has his first Gymbattle at the Pewter Gym.
- Ash forfeits his battle against Brock, suffering his first loss.
- Ash's Pikachu learns Thunderbolt.
- Ash has a rematch with Brock, but eventually forfeits again.
- Brock follows Ash and gives him his first Badge, the Boulder Badge.
- Brock joins Ash and Misty, leaving the Pewter Gym in his father's care.
|Clefairy and the Moon Stone|
|Water Flowers of Cerulean City|
|The Path to the Pokémon League|
|The School of Hard Knocks|
|Bulbasaur and the Hidden Village|
|Charmander the Stray Pokémon|
|Here Comes the Squirtle Squad|
|Mystery at the Lighthouse|
|Electric Shock Showdown|
|Battle Aboard the St. Anne|
|Island of the Giant Pokémon|
|Beauty and the Beach|
|Tentacool and Tentacruel|
|The Ghost of Maiden's Peak|
|Abra and the Psychic Pokémon|
|The Tower of Terror|
|Haunter Versus Kadabra|
|Primeape Goes Bananas|
|Pokémon Fashion Flash|
|The Punchy Pokémon|
|Sparks Fly for Magnemite|
|Dig Those Diglett|
|The Ninja Poké-Showdown|
|The Flame Pokémon-athon|
|The Kangaskhan Kid|
|The Bridge Bike Gang|
|Ditto's Mysterious Mansion|
|The Battling Eevee Brothers|
|Wake Up Snorlax!|
|The March of the Exeggutor Squad|
|The Problem with Paras|
|The Song of Jigglypuff|
|Attack of the Prehistoric Pokémon|
|Who Gets to Keep Togepi?|
|Bulbasaur's Mysterious Garden|
|Princess Versus Princess|
|The Purr-fect Hero|
|The Breeding Center Secret|
|Riddle Me This|
|Beach Blank-Out Blastoise|
|The Misty Mermaid|
|The Battle of the Badge|
|It's Mr. Mime Time|
|Showdown at the Po-ké Corral|
|Mewtwo Strikes Back|
|The Evolution Solution|
|Make Room for Gloom|
|Go West Young Meowth|
|To Master the Onixpected|
|The Ancient Puzzle of Pokémopolis|
|Bad to the Bone|
|All Fired Up|
|Round One - Begin!|
|Fire and Ice|
|The Fourth Round Rumble|
- Gary is revealed to have made it to the fourth round.
- Gary loses his fourth round battle against Melissa, placing him in the Top 32.
- Gary heads back to Pallet Town.
- Ash uses his Muk in battle for the first time.
- Ash's Muk is revealed to know Body Slam.
- Ash wins his fourth and final preliminary round match against Jeanette Fisher and advances to the fifth round, securing him a place in the Indigo Stadium.
|A Friend In Deed|
|Friend and Foe Alike|