Vulvovaginal candidiasis (VVC) is a highly prevalent condition that has a major impact on women’s quality of life and health, and it is a major treatment challenge. The growing need for intensive antifungal therapies has contributed to the emergence of drug-resistant Candida strains. Effective treatment options that address antifungal resistance and control highly resilient biofilms are therefore urgently needed. This study aimed to investigate the antifungal activity of essential oils (EOs) against drug-resistant Candida vaginal isolates. Method: The antimicrobial effect of tea tree, niaouli, white thyme, and cajeput EOs on the planktonic growth of Candida isolates was first evaluated using an agar disc diffusion method. Then, the vapor-phase effect of tea tree EO (VP-TTEO) on biofilm formation and on pre-formed biofilms was assessed using crystal violet staining, the XTT reduction assay, colony-forming unit enumeration, and scanning electron microscopy. Results: The results showed high antifungal activity of EOs against drug-resistant Candida isolates. In addition, VP-TTEO had a significant inhibitory effect on biofilm formation in all tested isolates and was able to cause a marked reduction in mature Candida albicans biofilms. Conclusions: Overall, this study suggests that VP-EO may be a promising solution to prevent biofilm-related VVC caused by antifungal-resistant strains.