AbstractMillions of adenosine (A) to inosine (I) RNA editing events are reported and well‐studied in eukaryotes; however, many features and functions remain unclear in prokaryotes. By combining PacBio Sequel, Illumina whole‐genome sequencing, and RNA Sequencing data of twoKlebsiella pneumoniaestrains with different virulence, a total of 13 RNA editing events are identified. The RNA editing event ofbadRis focused, which shows a significant difference in editing levels in the twoK. pneumoniaestrains and is predicted to be a transcription factor. A hard‐coded Cys is mutated on DNA to simulate the effect of complete editing ofbadR. Transcriptome analysis identifies the cellular quorum sensing (QS) pathway as the most dramatic change, demonstrating the dynamic regulation of RNA editing onbadRrelated to coordinated collective behavior. Indeed, a significant difference in autoinducer 2 activity and cell growth is detected when the cells reach the stationary phase. Additionally, the mutant strain shows significantly lower virulence than the WT strain in theGalleria mellonellainfection model. Furthermore, RNA editing regulation ofbadRis highly conserved acrossK. pneumoniaestrains. Overall, this work provides new insights into posttranscriptional regulation in bacteria.