**1. Introduction**

The emergence of multidrug-resistant (MDR) bacteria is correlated with selective pressure caused by the indiscriminate use of antibiotics, which reduces therapeutic options available [1]. Consequently, it leads to a serious public health problem frequently associated with increase of healthcare costs and high morbimortality rates [2]. One worldwide recognized bacterial pathogen with the ability to develop severe clinical conditions such as pneumonia and septicemia is *Staphylococcus aureus* [3]. Historically, this bacterium has shown a great ability to become resistant to several antibiotics [4]. Furthermore, *S. aureus* has a highlighted ability to build surface-associated bacterial communities, called biofilm, being one of the most determinant factors for the development of chronic infections, and it is the major cause of treatment failure [5–7].

Recently, the use of natural compounds, such as EOs obtained from different parts of the plants, is receiving attention for their biological activities, including antioxidant, anti-inflammatory, and anticancer effect [8]. Moreover, EOs have been frequently mentioned on scientific literature as a promising antimicrobial agent, being effective against a wide range of pathogenic bacteria and yeast [9, 10]. Thus, this chapter will present a comprehensive overview about general features of *S. aureus*, including virulence factors, antibiotic resistance, and biofilm formation. Additionally, it will introduce the EOs used as potential therapeutic approaches against biofilm of multidrug-resistant *S. aureus*.
