The ocular bacterial infections can result in serious loss of vision. The antibiotics thus play a critical role in manipulating the bacterial flora to ensure ocular health and to eradicate infection. Systemic and topical antibiotics are used in the treatment of numerous ocular infections like blepharitis, conjunctivitis, keratitis, orbital cellulitis, dacryoadenitis, dacrocystitis, and endophthalmitis. Each type of ocular infection has different causative agents and therefore different types of recommended antibiotics. Several basic principles of pharmacology are necessary to understand the concept of antibiotics in the eye. Some of the classes of ocular antibiotics explained in the chapter are aminoglycosides, sulfonamides, fluoroquinolones, polypeptides, macrolides, corticosteroids, and fortified antibiotics. The chapter also discusses about the antibiotic resistance, and antibacterial concepts, along with graphs and table contents.