The Bowsers, in the following cutscene, decide that the other has outgrown their usefulness, and that they "annoy the other to no end", so they conspire with their respective Kamek on how to get rid of the other. Both plans are the exact same, having to do with the book. At Petalburg, Bowser finds what he thinks is Peach and talks to her, but eventually finds out that he is really speaking to a poster. Bowser is also involved in two of his Bowser minigames. The first is Pit Boss, in which players must dodge spiked balls tossed into an arena by Bowser. The second is Dark 'n Crispy, in which the players must avoid Bowser's fiery breath in the dark. He is not involved in Dizzy Rotisserie, the third Bowser minigame, but is watching from a platform overhead. Bowser is also faced on the final stage and special stage on Stage Clear mode. His health is depleted by stringing together multiple combos. Part of Super Mario Galaxy's final battle “From this galaxy, I'll rule a great galactic empire with Peach by my side. It will last forever! I will rule every pitiful corner of the universe. So, Mario, as you can see, I got big plans. And stomping you is at the top of my list!” — Bowser, Super Mario Galaxy

Bowser is playable again in Mario & Sonic at the Olympic Games Tokyo 2020, again being a Power-type character. He is also among the eight playable characters in the Tokyo 1964 events, using his sprite from Super Mario Bros., where he has Hammer Bros. as his teammates in Volleyball. In the opening cutscene, Bowser has green hands, while his in-game sprite resembles his normal appearance except that his tail is green and has no spikes. Bowser often works together with Dr. Eggman during the Mario & Sonic series, often causing trouble to disrupt the Olympics or defeat their nemeses, Mario and Sonic. Bowser and Eggman mutually treat each other as equals in their partnerships as well as friends, which is prominently shown in London. In Tokyo, Bowser trusts Eggman's comprehension of Tokyo '64 when they end up trapped in the game so they can outwit Mario and Sonic and escape.

Artwork of Bowser from Mario & Luigi: Dream Team “Give it to me straight. Princess Peach is gone? Hello? That is MY thing! Only I get to kidnap her!” — Bowser, Mario & Luigi: Dream Team On the board Bowser's Gnarly Party, Bowser is located at a certain point on the board that changes when a Star is collected, waiting for a player to pass by him and do various things to them depending on their current size. If the player is normal size, Bowser breathes fire, causing the player to lose half their coins. If the player is miniature size, Bowser uses his fire to send them to a different starting point. If the player is mega-sized, Bowser challenges them to a game of Bowser Wrestling or Panels of Doom; winning causes Bowser to leave until the next Star is claimed, and losing causes Bowser to take half the player's coins. He also occasionally miniaturizes everyone for one turn. In " Just Deserts," Koopa creates a mirage machine, which he uses to create a mirage of the Mushroom King splashing around in an oasis in the middle of the desert Mario and Luigi are trapped in, while he stays at his underground base. However, once they reach the spring, Koopa deactivates the mirage, prompting the bros to search for the king. They eventually arrive at the pyramid Koopa's base is in, and Mario rescues the king and presses a "master mirage" button on the machine, destroying the fortress.

Several of Bowser's Lakitus capture Toadstool, and Bowser places her in the custody of his kids, telling them to keep a video line between his castle and theirs open. She is kept in a jail cell inside their castle. After interrupting them playing a video game, Bowser begins to tell his kids that he proposed to Toadstool, but is interrupted by a Magikoopa who informs him that the model of his cake is finished. Bowser is shown the model, but wants it bigger, and has to interrupt his children's video game again to tell them to keep Toadstool inside the castle.For the Wii U port of Bayonetta and its sequel, Bayonetta 2, Bayonetta is able to summon Bowser while wearing the Princess Peach costume, although only Bowser's arm and legs are visible during the summon [18]. Defeated, the Koopa King admits that he only wanted the keys as a remedy for his tone-deafness. Before Mario and Toad leave, Mario uses the power of the keys to turn Bowser's Castle and the land surrounding it into a paradise. Afterward, the three start dancing, and cannot stop; Toad explains that, when they recaptured the keys, some music was implanted into their souls. The three then continue dancing. Bowser is later seen in the credits, where he is dancing in front of his castle. In the Super Mario Bros. game style, Bowser simply moves left and right while breathing fireballs that vary in altitude. He may also do a small jump during the process. The Super Mario-kun manga published by Pikkapika Comics also features Bowser as a prominent character and antagonist. The third board he appears on is the Bowser-themed board of the game, Infernal Tower, one of the Solo Mode boards. If the player passes the final space, a cage falls around them, which Bowser, in his Koopa Clown Car, then carries away.