The increase of resistant bacteria puts a huge pressure on the antimicrobials in current use. Antimicrobial resistance (AMR) results from antibiotic misuse and abuse over many years and is a global financial burden. New polices must be developed for the use of antimicrobials and to continue research efforts to mitigate AMR. It is essential to target the most harmful bacteria and concentrate on their mechanisms of resistance to develop successful antimicrobials. Essential oils (EOs) are occur naturally in plants and have long been used as antimicrobials, but most have not been researched. This review explores EOs as alternative antimicrobials, investigating their ability to decrease or inhibit biofilm formation, and assess their ability to contribute to AMR control. Low concentrations of EOs can inhibit Gram-positive and Gram-negative pathogenic bacteria. Some EOs have demonstrated strong anti-biofilm activities. If EOs are successful against biofilm formation, particularly in bacteria developing AMR, they could be incorporated into new antimicrobials. Therefore, there is a need to investigate these EOs’ potential, particularly for surface disinfection, and against bacteria from food, clinical and non-clinical environments.