Siena Castellon (she/her) is an 18-year old neurodiversity advocate and author from Ireland who lives in the United Kingdom. She is autistic, dyslexic, dyspraxic and has ADHD. When she was 13, she discovered that online resources were focused on supporting the parents of children with special educational needs (SEN). Siena decided to address this by creating www.qlmentoring.com, a website that supports SEN students. Most recently, Siena launched Neurodiversity Celebration Week, an international campaign that aims to challenge negative perceptions and stereotypes about autism and learning differences by encouraging schools to flip the narrative from focusing on the challenges of being neurodivergent to focusing on strengths and talents. Over 760 schools and over half a million students from around the world took part in 2020. Siena is also the bestselling author of The Spectrum Girl's Survival Guide: How To Grow Up Awesome and Autistic and The Spectrum Girl's Survival Toolkit: The Workbook for Autistic Girls. When she found that most books were written for autistic boys and that there were no books aimed at supporting the unique challenges faced by autistic teen girls, Siena decided to change this. In April 2020, she launched a successful crowdfunding campaign to raise funds to donate a book to every state school for girls in the United Kingdom.