Pseudomonas aeruginosais a ubiquitous opportunistic pathogen that can cause severe respiratory tract infections. Geraniol, a chemical component of essential oils, has antimicrobial and anti-inflammatory activities, along with low toxicity. However, the effect and mechanism of geraniol againstP. aeruginosavirulence factors are rarely studied. In this study, we investigated the quorum sensing (QS) inhibitory effects and mechanisms of geraniol againstP. aeruginosaPAO1, using physiological and biochemical techniques, quantitative reverse transcription polymerase chain reaction, and transcriptomics. Geraniol slightly affectedP. aeruginosaPAO1 growth, prolonged the lag phase, and delayed growth periods in a concentration-dependent manner. Geraniol inhibited three QS systems ofP. aeruginosa,las,rhl, andpqsby suppressing the expression level of their key genes, including the three signal synthetase encoding genes oflasI,rhlI, andpqsABCDEH, and the corresponding signal receptor encoding genes oflasR,rhlR, andpqsR. Geraniol also suppressed certain virulence genes regulated by these three QS systems, includingrhlABC,lasAB,lecAB,phzABMS, andpelABG, resulting in the attenuation of the related virulence factors, rhamnolipids, exoprotease LasA, elastase, lectin, pyocyanin, and biofilm. In conclusion, geraniol can suppress the virulence factors ofP. aeruginosaPAO1 by inhibiting the three QS systems oflas,rhl, andpqs. This study is significant for improving the treatment of bacterial infections caused byP. aeruginosa.