Introduction <p>Thyroid cancer is among the most rapidly increasing endocrine malignancies globally. Despite its rising incidence, public awareness and knowledge of its risk factors, symptoms, and related factual items (e.g., screening indication, sex differences, iodine) remain limited. This study aimed to assess the level of awareness and knowledge of thyroid cancer among Malaysian adults and to examine the sociodemographic factors associated with these outcomes.</p> Methods <p>An online cross-sectional survey was conducted from November 2024 to March 2025 among Malaysian adults. A previously validated, self-administered questionnaire was adapted and distributed via Google Forms through Facebook and WhatsApp. Inclusion criteria included being a Malaysian adult, residing in Malaysia, and able to understand English or Malay.</p> Results and discussion <p>A total of 219 valid responses were collected. Overall, 74.7% of participants had heard of thyroid cancer, indicating a moderate level of awareness (mean score = 3.56). 61.6% of respondents demonstrated good knowledge, which was significantly associated with higher education levels, professional occupation, and previous exposure to thyroid cancer information (<i>p</i> &lt; 0.05). A weak yet statistically significant positive correlation was found between awareness and knowledge scores (rs = 0.148, <i>p</i> = 0.014). Other sociodemographic variables showed no significant association.</p> Conclusion <p>This study revealed a moderate level of awareness and a good level of knowledge about thyroid cancer among Malaysian adults. Differences in awareness and knowledge were observed across selected sociodemographic groups, including ethnicity, education level, and prior exposure to thyroid cancer information. These findings highlight the need for targeted public health initiatives and tailored educational interventions to address gaps in thyroid cancer literacy and support early recognition efforts.</p>