In Shakespeare's The Merchant of Venice, Salerio and Antonio are friends, and this friendship explains Salerio's great concern for Antonio and Antonio's wellbeing. Salerio is also a Venetian gentleman and merchant, and his role in the play is intertwined with the role of Salarino, another gentleman and friend to Antonio. Because the names of these two characters are so similar, and because there are two other characters in the play with similar-sounding names, many scholars find Salerio and Salarino to be relatively minor characters whose main function in the play is to keep the plot moving forward.

Salerio's friendly connection to Antonio is clear but underdeveloped; for example, Salerio explains at one point that his primary responsibility to Antonio is to help him feel like he is a good mood. Salerio, as a minor character, supports the more important roles in the play, like those of Antonio and Bassanio.