Little is known about weight stigma in sexual minority women, and even less is known about weight stigma in those who have attained substantial weight loss and maintenance. This study examined weight stigma experiences and internalization in sexual minority women from the National Weight Control Registry (NWCR) who had lost ≥30 pounds and maintained this weight loss for ≥1 year, and compared weight stigma levels between sexual minority women versus heterosexual women in the NWCR. NWCR participants completed an electronic survey. Women who identified as a sexual minority (n = 64; 98% White; MBMI = 29 ± 8; Mage = 47 ± 13) and heterosexual women matched on body mass index (BMI), age, and race (n = 64; 98% White; MBMI = 28 ± 7; Mage = 51 ± 13) were included. Participants completed assessments of experienced and internalized weight stigma. Generalized linear models showed that a significantly larger proportion of sexual minority women in the NWCR reported experiencing weight stigma in the past year (24.2%) compared with heterosexual women (4.7%; p < .05). Furthermore, sexual minority (vs. heterosexual) women reported significantly higher levels of internalized weight stigma (p < .001), and a greater proportion of sexual minority women (35%) reported clinically significant internalized weight stigma relative to heterosexual women (2%; p < .001). Sexual minority women are at greater risk for experienced and internalized weight stigma than their heterosexual counterparts among women who have attained significant long-term weight loss. It is critical to expand research on weight stigma in sexual minority women.