A brand ambassador (sometimes also called a corporate ambassador) is a person engaged by an organization or company to represent its brand in a positive light, helping to increase brand awareness and sales. The brand ambassador is meant to embody the corporate identity in appearance, demeanor, values and ethics. The key element of brand ambassadors is their ability to use promotional strategies that will strengthen the customer-product-service relationship, influence a large audience to buy and consume more.

Predominantly, a brand ambassador is known as a positive spokesperson, an opinion leader or a community influencer, appointed as an internal or external agent to boost product or service sales and create brand awareness. Today, "brand ambassador" as a term has expanded beyond celebrity branding to self-branding or personal brand management. Professional figures, such as good-will and non-profit ambassadors, promotional models, testimonials and brand advocates have formed as an extension of the same concept, taking into account the requirements of every company.

The term brand ambassador loosely refers to a commodity which covers all types of event staff, varying between trade show hosts, in-store promotional members and street teams. Previously, the job of a brand ambassador was undertaken typically by a celebrity or a public figure, who get paid adequately for their time and effort. Nowadays however, a brand ambassador can be anyone who has knowledge or can identify certain needs of the brand. The fashion industry still solely rely on celebrity clientele in order to remain brand ambassadors. Furthermore, brand ambassadors are considered to be the key salesperson for a product or service on offer. They must remain well-informed when it comes to the brand they are representing, due to their nature of being the go-to person when questions arise from consumers. The brand ambassador's job is to drive results through communication tools either publicly, such as social media, or privately including emails, messaging and further one-to-one channels.