Japanese clothing company Uniqlo held a competition called the UT Grand Prix for a winner to have their artwork used for a t-shirt to be worn in-game and receive $10,000, with the grand-prize winner being Chinese artist Li Wen Pei. However, it was later discovered that Wen Pei had broken the contest's rules causing him to be disqualified and the grand prize not being awarded to another entrant. Though not explicitly stated by Uniqlo as to why he was disqualified, it's believed this was due to Wen Pei having used his design for his own commercial purposes such as on phone cases and t-shirts, which goes against the competition's rules. Wen Pei's design featured a Gyarados sitting atop a trio of Magikarp presented in a totem style.

There is a very rare chance that a Pokémon in the wild will come to the player's Pokémon camp while they are playing in it and ask to join the player's team. If the player selects the "Yes" option then not only will the Pokémon be able to join the camp but the Player will have also "caught" the Pokémon without battling it (it will go into one of the Player's Poke balls).

Outside of Sirchester there is an NPC who states that he swam from the Kalos Region (from Pokémon X & Y) to the Galar Region. If what he says is true then this confirms that the two regions are in close proximity to each other just like their real-world European counterparts of the United Kingdom (Galar) and France (Kalos), which, in real life, are very close but separated by the English Channel.

In the games' data are the unused moves Celebrate, Hold Hands, Matt Block, and V-Create. They are not programmed to a single Pokémon in-game and Metronome will not turn into them.

The Galarian Yamask has one of the most elaborate evolutionary methods in the entire series. In order to evolve it, the player must allow Yamask to lose 49 or more points of HP and then, with the damaged Yamask, the player must go under the large stone arch in the Dusty Bowl area. Immediately upon doing the latter, Yamask will evolve into it's Galar-exclusive Evolution, Runerigus.

In the Eastern side of the Hammerlock Pavilion there is a little girl who asks the player to deliver a message to her friend in Ballonlea. However, when the player delivers it to said friend, they find that he is actually a middle-aged man. Adding to the eeriness of the scene, the man claims that the girl who sent the letter was a friend of his who he hasn't seen since childhood. If the player returns to where the child was, she won't be there, and if the player searches the exact area she was on, they will instead find a hidden Reaper Cloth (An item important to Ghost-type Pokémon), implying she may have been a ghost. Furthermore, if the player goes back to the man's house, a child will be standing facing the wall and state that she is having a conversation with someone. This seem to be part of a string of similar "Ghost Girl" Easter eggs seen in recent main-line Pokemon games,

After setting their birthday with the NPC in Wedgehurst, if the player makes curry in the game on their birthday, a single candle and other party-themed things will be added to the Human curry.

The unique new fossil Pokémon of Sword and Shield and their even more unique mix-and-match gimmick are a reference to Paleontological history. Some of the earliest recorded Dinosaur bones and discoveries were found by British scientists (the Galar Region is based on the United Kingdom) and during the earliest discoveries many of those scientists, due to knowledge of these newly-discovered prehistoric beasts being very primitive at the time, did reckless things and made a lot of rather egregious mistakes including taking bones from one species of Dinosaur and applying them to another species' bones, both believing and claiming that they were of the same species. This is reflected in the gimmick where two of the player's fossils are fused into one of four Pokémon that clearly look like the parts used to fuse them do not match to the point that even the Pokédex descriptions seem baffled at their existence and how they are still alive. The scientist in-game who does this is called Cara Liss, or "careless".

Before Sword and Shield's release, nearly the entire game was leaked onto a Discord server by four users. The Pokémon Company decided to take action almost a week after the games officially released by filing a lawsuit against those four users. Perkins Coie LLP, the international law firm hired to represent The Pokémon Company during this case, believed that the company was “[harmed and disrupted in] its ability to market Pokémon Sword and Pokémon Shield” and issued subpoenas to Discord as well as the website 4chan where the leaks were also posted in an effort to try and identify the perpetrators.

Leon's battle theme in the Battle Tower, composed by Undertale and Deltarune creator Toby Fox, appears to interpolate the track "A Baby Legend - The Baby is 2", from The Baby is You, a 2010 concept album by Fox based on the webcomic Homestuck. The choice of interpolation garnered attention for its strangeness by the standards of a Nintendo-affiliated game, as The Baby is You was a joke album about male pregnancy, made to poke fun at the Homestuck forum's rule against fanart surrounding the topic.

The Pokémon Centers in the game were inspired by British pubs that concept art designer Shigeru Ohmori saw throughout the United Kingdom during a trip there. The intention was to portray an area in the Galar region were people of all kinds could come to hang out and watch the spectacle of the region's Broadcasted Gym Battles.

In early 2021, a man from Nagoya, Japan was arrested after hacking and modifying Pokémon in his copy of the game and selling them to people. The Japanese police and The Pokémon Company felt this was in violation of the country's "Unfair Competition Prevention Act (UCPA)" and therefore illegal. The man was first brought to the police's attention after selling a modified Sobble for ¥4,400 (US$42), but he was eventually able to make ¥1.15 million (US$11,000) from various transactions before being arrested. It's suspected that the reason for trading these hacked Pokémon was due to the potential ability changes that hacking allowed which could provide easy advantages in the competitive scene without going through the time to catch them in-game.

When Pokémon Sword and Shield were announced, they inspired a slew of memes from British internet users who found humor in the influences their culture provided towards the games. One meme, made by Twitter user Callum O'Dwyer, depicts a PokéMart from Pokémon: Let's Go, Pikachu! edited to show the logo of Greggs, a UK bakery chain. After the tweet proved viral, O'Dwyer reached out to Greggs to ask if the tweet was "worth a couple of [steak] bakes" as compensation for the free advertising. In response, Greggs gave him a £10 coupon and told him to "have a steak bake or three on us".