A man's man is a man who engages in activities which are traditionally viewed as masculine, and who earns the respect of other men. You may also hear a man's man described as “manly,” emphasizing his masculine personality. Such men tend to be domineering, confident, and bold, because these character traits are reinforced by traditional gender roles.

Human society shifted radically in the 20th century, in no small part because of the efforts of the feminist community. A major breakdown of traditional gender, race, and cultural roles occurred, leaving some people with a sense of being adrift or unclear about their roles in life. As a result, the definition of manliness and what it meant to be a man began to change, and the concept of a “man's man” acquired fresh connotations, distinguishing such men from their more feminine or gender-fluid counterparts.

Activities which a man's man might enjoy include: hunting, fishing, playing or watching sports, grilling, construction projects, camping, and equipment maintenance and repair. In the traditional framework of gender roles, such tasks are viewed as extremely masculine, and indeed they continue to be dominated by men, with a smaller number of women engaging in these activities as a general rule. A man's man may also distinguish himself from other men by proving that he has been engaging in these activities since childhood, rather than picking them up as a hobby later in life.

Other men are often respectful of a man's man because of his skills and personality. Some men feel threatened by the shifting gender roles in many societies, so they may admire masculine men because they epitomize gender ideals. Others simply feel drawn to the man's man, either because they are masculine men themselves, or because they have a fondness for manly men.

As a general rule, a man's man prides himself on being practical, tough, sensible, and logical. He believes that he can solve any problems which might be thrown at him with aplomb, and he is prepared for a range of situations. A man's man may also prefer “roughing it” while working on projects, eschewing creature comforts for the bare essentials, and stressing self-reliance and ingenuity as valued character traits. Many also consider themselves to be gentleman, with old-fashioned manners and a complex personal code of behavior.

Some people find the culture of the man's man off-putting. People who reject traditional gender roles may dislike the heavy emphasis on masculine activities, for example, while people who think that sensitivity is an important characteristic may struggle to relate to a man's man. Other people point out that the man's man has been held up as a prime example of how to behave for quite a long time in literature, film, and song, and that centuries of praise for manly men can't be all wrong.