Consumers’ changing perception of masculinity has created a problem for brand strategists and advertisers. Since masculinity is now branded, and men are increasingly marketed to and offered visions of masculinity for consumption, masculinity is now considered to be one of the most prominently used social resources within advertising. However, it is difficult to create a masculine brand personality and depict masculinity in a way that will resonate with the audience and not create an intense backlash from consumers and society. This issue is particularly pressing when a brand is communicating with younger audiences aged 15–24 years (Generation Z) and aged 25-35 (millennials) that have been influenced by popular culture besides more traditional upbringing. The topicality of the Doctoral Thesis research is related to the challenges the brand strategists and advertisers face concerning the ever-changing consumer perceptions of masculinity. Given the importance of masculinity in advertising, this research is relevant in terms of both marketing and economic considerations. To achieve the goal of the Thesis, masculinity as a concept, various types of it, and consumer perception influencing factors of it are analyzed. Brand personality theories are used to create a theoretical framework for assessing masculinity depiction in brand personality and advertising. The research answers what Latvian Generation Z and millennial consumers think about masculinity in advertising and which brand archetypes, brand personality dimensions, and types of masculinity are the most preferable in advertising. The developed methodology of creating a masculine brand personality was applied and approved in various companies such as Madara Cosmetics, advertising agency WKND and their client Virši-A, and communication and media agency Dentsu Latvia. The Doctoral Thesis has been written in English. It comprises an introduction, four chapters, conclusions, recommendations, and a list of references of 194 sources. It has been illustrated with 44 tables and 44 figures. The volume of the Thesis is 190 pages, excluding 43 annexes.