Celebrations was released on October 8, 2021 and, as with previous special expansions such as Shining Fates and Champion's Path, could only be found in specifically-branded merchandise. Its Japanese equivalent, the 25th Anniversary Collection, was released on October 22, 2021. Both sets feature Legendary and Mythical Pokémon from across the span of the franchise in addition to a selection of different Pikachu cards. Some of these revisit concepts from the Original Series and update them with mechanics and aesthetics from the Sword & Shield Series. Several promotional cards included in Celebrations merchandise similarly feature previous TCG mechanics Dark and Light Pokémon, δ Delta Species, Pokémon ☆, Pokémon LV.X, Pokémon SP, and Pokémon Prime with species introduced after they were discontinued. Most of these "remixed" cards have the clause (This card cannot be used at official tournaments.) under the copyright. These cards, as well as those included in the Celebrations expansion, feature the Pokémon 25th Anniversary logo, while all cards from the 25th Anniversary Collection feature a blue and gold "25th" graphic. There is no Reverse Holo parallel set for Celebrations. Each Celebrations booster pack contains four cards; each 25th Anniversary Collection pack contains five.
Celebrations also has a 25-card Classic Collection subset comprising close replicas of popular cards from previous Series, which feature etching and a Confetti Holofoil pattern. The cards retain the original numbering, rarity, and copyright information of their original print—except for those released during the Original and Neo Series, which omit the Wizards of the Coast copyright. As with the "remixed" cards, they are ineligible for use in official events (aside from cards which are legal in Expanded in their original printing, which are legal in Expanded) and feature the Pokémon 25th Anniversary logo. The Japanese equivalent of this subset was the Promo Card Pack 25th Anniversary Edition, a separate promotional set distributed exclusively as single-card packs.