The Prince Jewel Keys (プリンスジュエルキー Purinsu Jueru Kī?) are the main collectible items for the Happy! Prince PreCure season. The Prince Jewel Keys come in the Cures' respective gemstones, which allows the boys to transform into their Cure Forms once inserted into their Prince Link. Once all of the Prince Jewel Keys are collected, their power goes straight to the Pegasus Kingdom.
The Prince Jewel Keys have the ability to unlock the Prince Link to enable the boys' transformations. They are also used to free people from their crystalline caskets and restore their dreams that were taken by the Tempest Kingdom as well as perform their first finishing attacks. The Prince Jewel Keys come in the Cures' respective colors, gemstones, and elemental abilities and once all of the Prince Jewel Keys are collected, their power goes to the Pegasus Kingdom.
Newer Prince Jewel Keys: the Ruby, Rose Quartz, Topaz, Peridot, and Tanzanite Keys are used for the Crystal Prince Swords and perform the Royal Infinity Guard finishing attack. The Sunstone, Rubellite, Citrine, Chrome, and Aquamarine Prince Jewel Keys are used to perform the Five Star Explosion finishing attack.
- Cure Phoenix uses his Crystal Prince Sword with his Ruby Key to performDragon Fire and the Sunstone Key to perform Sunlight Fire .
- Cure Saint uses his Crystal Prince Sword with his Rose Quartz Key to perform Unicorn Shoot and the Rubellite Key to perform Comet Shoot.
- Cure Zeus uses his Crystal Prince Sword with his Topaz Key to perform Raichou Thunder and the Citrine Key to perform Starlight Thunder.
- Cure Armor uses his Crystal Prince Sword with his Peridot Key to perform Gryphon Impact and the Chrome Key to perform Blooming Impact.
- Cure Charming uses his Crystal Prince Sword with his Tanzanite Key to perform Merman Tornado and the Aquamarine Key to perform Freezing Tornado.
- The Prince Jewel Keys function the same as the Dress Up Keys from Go! Princess PreCure.