Quorum　sensing　(QS)　plays　a　pivotal　role　in　bacterial　interactions　and　is　crucial　for　enhancing　the　efficiency　and　stability　of　biological　wastewater　treatment　(BWT)　systems.　However,　the　diversity　of　BWT　processes　and　the　complexity　of　QS　pose　challenges　to　understanding　their　functionality.　This　review　uses　bibliometric　tools　to　synthesize　research　from　the　past　two　decades,　capturing　the　significant　growth　in　research　in　this　field　driven　by　China,　Korean,　and　U.S.　researchers.　The　research　hotspot　has　shifted　from　initial　basic　research　on　＇gene　expression＇　and　＇biofilm　formation＇　to　applied　studies　on　＇start-up＇,　＇denitrification＇,　＇nitrification＇,　and　＇temperature＇,　along　with　interdisciplinary　explorations.　Keyword　cluster　analyses　reveal　key　themes,　including　quorum　quenching,　biofilm　formation,　membrane　fouling,　and　antibiotic　resistance　genes.　Subsequently,　this　review　explores　current　applications　and　mechanisms.　Enhanced　QS　promotes　pollutant　removal　through　modulation　of　microbial　metabolism　and　energy;　enhances　microbial　robustness　through　modulation　of　extracellular　polymeric　substances　(EPS),　resistance　to　oxidative　stress,　and　activation　of　specific　genes　and　transporter　proteins;　and　facilitates　biofilm　and　granular　sludge　formation　through　modulation　of　adhesion　and　EPS.　Additionally,　weakening　of　QS　mechanisms　reduces　membrane　fouling　and　mitigates　sludge　bulking　by　inhibiting　community　behavior　and　modulating　EPS.　It　also　summarizes　reported　QS　regulatory　strategies,　including　chemical　activators/inhibitors,　sustainable　bioregulation　using　specific　microbes,　and　engineering　approaches　for　optimizing　environmental　conditions　and　design　parameters.　Future　research　should　focus　on　deepening　understanding,　exploring　optimization　potential,　and　investigating　sustainability　and　ecological　safety　to　maximize　the　potential　of　QS　in　BWT　systems　and　gain　key　insights　into　the　application　of　QS　technologies.　©　2024　Elsevier　Ltd