With the Internet’s expansion, various online platforms have arisen, allowing people to express their views and influence electronic word-of-mouth (eWOM) for various brands. Depending on their personalities, some Internet users may express dissatisfaction or exhibit anti-brand behaviors when they receive products or services that don’t meet their expectations. Not all users, however, come to the brand’s defense, even if they disagree with the critics or anti-brand behaviors. Through a case study using netnography, we explored the influence of personality on online brand defense. We found that individuals seeking social recognition and self-validation are more likely to engage in online brand defense. Recognizing the impact of personality on online behavior can assist businesses and marketers in formulating strategies for fostering positive interactions with consumers.