The workplace is one of the areas in which discrimination most frequently occurs. Despite increasing workforce participation among older adults and the adverse effects of workplace discrimination on the physical and psychological wellbeing of older adults, limited attention has been given to workplace discrimination against older workers. Based on a national survey of 420 older workers age 50 and above, this study first examined the prevalence of perceived workplace discrimination. Results indicated more than 81 per cent of the older workers encountered at least one workplace discriminatory treatment within a year. Prevalence of perceived workplace discrimination differed with age, gender, education, occupation and wage. The study further tested two competing hypotheses on the level of perceived workplace discrimination and found mixed support for both. As hypothesised (based on the social barriers theory), lower education and racial/ethnic minority status were positively associated with perceived workplace discrimination. As counter-hypothesised (based on the attribution-sensitivity theory), younger ages and being male were positively associated with perceived workplace discrimination. In examining the roles of supervisor and co-worker support, the study discovered that supervisor support was negatively associated with workplace discrimination. Finally, this study revealed a non-linear relationship between wages and perceived workplace discrimination, with the mid-range wage group experiencing the highest level of workplace discrimination.