Mermaid Heel (マーメイド・ヒール Māmeido Hīru 人魚の踵) is a powerful all-female Legal Guild in Konohagakure.
Mermaid Heel is very known as an all-female guild, with the entirety of its shown members being females. It's currently unknown whether males could be given access to the guild, since Hibiki Lates jokingly said he would have joined Mermaid Heel without being contradicted; Toby Horhorta, however, angrily commented the Blue Pegasus Mage "is way off their theme".
Mermaid Heel location is outside the mainland in Amazon Lily where its inhabitants is only female.
Mermaid Heel is consider a very powerful guild. The members are chosen amongst the strongest women in Amazon Lily as the belief strength equals beauty. Many members are capable of using Haki, thus making them formidable opponents to defeat. Most of Mermaid Heel's power and reputation seems to stem from its strongest Mage, Kagura Mikazuchi and the Guild Master Boa Hancock. Kagura has been described as being on the same if not higher level as Erza Scarlet, one of Fairy Tail's S-Class Mages, as well as the guild's most powerful female member while Boa Hancock, being a wizard saint, is a testament of her strength.