A bromance is a very close and non-sexual relationship between two or more men. It is an exceptionally tight, affectional, homosocial, male bonding relationship exceeding that of usual friendship, and is distinguished from normal friendship by a particularly high level of emotional intimacy. The emergence of the concept since the beginning of the 21st century has been seen as reflecting a change in societal perception and interest in the theme, with an increasing openness of Western society in the 21st century to reconsider exclusivity constraints. The female version of the bromance is the womance.

Bromance is a portmanteau of bro (or brother) and romance. Dave Carnie is credited with coining the term as editor of the skateboard magazine Big Brother in the 1990s to refer specifically to the sort of relationships that develop between skaters who spent a great deal of time together. The term did not attain broad currency until approximately 2005 when the theme became more prominent in the motion picture industry.

Bromance has been examined from viewpoints such as historiography, discourse analysis, social research, and queer theory in book-length reviews. The emergence of bromance as a topic over the past decade has been seen as reflecting how society has collectively changed its perception and interest in the theme.

Several characteristics of bromance have been cited:

According to Chen, society has taken a collective interest in reexamination of some of the traditional constraints on male friendship, and in potentially reshaping the constructs of gender, sexuality, and intimacy. Bromance provides "a case study of gender, sexuality, and exclusivity constraints in twenty-first century America as they operate in law and beyond. Those constraints in turn speak to the privilege and subordination imbued in this type of relationship, with implications for other types as well." This is distinct from the connotations of romantic friendship, a term of 20th century historical scholarship that retrospectively described close homosocial relationships, which had become less common after potential physical intimacy between non-sexual partners came to be regarded with anxiety in the second half of the 19th century.

On the one hand, social interest in the theme has been seen as driving the film industry, which has then fed back to society at large, exploring peoples' mindsets and addressing acceptance of "other types of relationships" between people. On the other hand, some have seen the emphasis on platonic love as a rejection of homoeroticism, or as a deliberate confounding of homosocial and homoerotic relationships.

Bromance has also been seen as a reflection of greater "discursive expressivity". The experiences of friendship and masculinity, perhaps due to more open parenting styles from the 1970s, reflect a trend toward more openness emotionally, with increased expressivity. According to sociologist Peter Nardi, "men are less afraid of being perceived as gay. It has become more acceptable for them to show some emotion." Men are marrying later, if at all, which impacts male bonding. According to the 2010 US Census, the average age of a man's first marriage is 28, up from 23 in 1960; men with more education are waiting until their 30s before getting married.

Some people, including Randall Munroe, have criticised the term "bromance" as a superfluous term for friendship, implying that it is unusual for two men to be close friends, when such relationships are deemed normal between women, and "friends", "close friends" or "best friends" would all be equally accurate and valid ways of expressing the same thing. The term has also been criticised as implicitly homophobic.