Mary-Belle Kirschner (born 23 October 1999), better known as Belle Delphine, is a South African-born British social media personality, pornographic actress, model, and YouTuber. Her social media accounts feature erotic and cosplay modelling, sometimes blending the two. Her online persona began in 2018 through her cosplay modeling on Instagram. Her posts on the platform were often influenced by popular memes and trends.

In mid-2019, Delphine gained notoriety through creating a satirical Pornhub account and selling her "GamerGirl Bath Water" product through her online store. Shortly after, her Instagram account was deleted due to community guideline violations and she went on hiatus. Upon returning to online content creation, she launched an OnlyFans account on which she posts adult content and began uploading YouTube music videos that were markedly explicit.

Media outlets have described Delphine as an "e-girl" and a cross between an internet troll and a performance artist. Delphine has also been cited as an influence on the e-girl style commonly adopted by TikTok users.