At eight years of age, her psychologist said that she was transgender, but she did not start calling herself Valentina until she was 12.
She has said in many interviews that she was not bullied for her gender identification.
In November 2016, she first walked her first runway at São Paulo Fashion Week. Soon after, L'Oréal made a short movie about Sampaio, which they released on International Women's Day, and later the company made her one of the company's brand ambassadors.
She is a L'Oréal Paris spokeswoman along with several other Brazilian women including: Grazi Massafera, Taís Araújo, Juliana Paes, Isabeli Fontana, Emanuela de Paula, Ágatha Moreira, and Sophia Abrahão.
In February 2017, Sampaio received international media attention after appearing on the cover of Vogue Paris and becoming the first transgender model to appear on the magazine's cover. Later that year, she also appeared on the covers of Vogue Brasil and Vogue Germany. She is the first openly transgender woman to be featured on both magazines' covers as well.
Other magazine cover appearances of Sampaio's include Vanity Fair Italia, Elle Mexico, and L'Officiel Turkiye. She has also worked with brands such as Dior, H&M, Marc Jacobs, Moschino, L'Oréal, and Philipp Plein.
- Okwodu, Janelle (10 July 2020). "Valentina Sampaio Makes History as Sports Illustrated's First Trans Model". Vogue. Retrieved 10 July 2020.
- Hanbury, Mary. "Victoria's Secret has reportedly hired its first openly transgender model. Here's everything we know about her". Business Insider. Retrieved 2019-08-05.
- Woodyatt, Amy (2019-08-05). "Victoria's Secret hires Valentina Sampaio, its first openly transgender model". CNN Style. Retrieved 2019-08-05.
- Ali, Rasha. "Valentina Sampaio makes history as first openly transgender Sports Illustrated Swimsuit model". USA TODAY. Retrieved 10 July 2020.
- "Modelo transgênera Valentina Sampaio é a nova porta-voz da L'Oréal Paris". Huff Post. 7 July 2016. Archived from the original on 10 December 2017. Retrieved 10 December 2017.
- "Primeira transexual capa da Vogue Paris, brasileira diz: "Evoluí com o preconceito"". Época. 19 February 2017. Retrieved 10 December 2017.
- "Valentina Sampaio em dose dupla na Vogue Brasil de dezembro". Vogue. 1 December 2017. Retrieved 10 December 2017.
- "Ícone trans, modelo Valentina Sampaio é destaque na Vogue alemã". Ig. 27 July 2017. Archived from the original on 10 December 2017. Retrieved 10 December 2017.
- "For Valentina Sampaio, Victoria's Secret Is Only the Beginning". Vogue. 8 August 2019. Retrieved 2019-08-09.
- Sloan, Elizabeth (2019-08-05). "Valentina Sampaio: 5 Fast Facts You Need to Know". Heavy.com. Retrieved 2019-08-06.