Objective <p>To explore the impact of oral care knowledge on the oral health behaviors of the older person.</p> Methods <p>A convenience sampling method was used to distribute online questionnaires to older adults aged 60 and above in Nanjing. A total of 314 questionnaires were distributed, and 294 valid questionnaires were collected, with an effective response rate of 93.63%.</p> Results <p>The awareness of oral health knowledge among the older adults aged 60 and above was inadequate (11.56%), with low awareness rates regarding, and knowledge related to oral cosmetology. The results from the adjusted Poisson regression analysis showed that monthly income ( <i>p</i> = 0.001), education level (<i>p</i> = 0.006), brushing frequency (<i>p</i> &lt; 0.001), toothbrush replacement (<i>p</i> = 0.008), mouth rinse after meals (<i>p</i> &lt; 0.001), dental plaque (<i>p</i> &lt; 0.001), sugar causes dental caries (<i>p</i> &lt; 0.001), treatment time (<i>p</i> &lt; 0.001), gum bleeding (<i>p</i> = 0.001), causes of bleeding (<i>p</i> = 0.001), the hazards of tooth loss (<i>p</i> &lt; 0.001), and the three major diseases (<i>p</i> = 0.011) remained the main influencing factors for oral health behaviors.</p> Conclusion <p>Oral health knowledge among the older adults in Nanjing is currently insufficient and represents a key modifiable factor influencing behavior. Targeted health promotion should prioritize populations with lower socioeconomic status and address critical knowledge gaps to improve oral health practices.</p>