Periodontitis and rheumatoid arthritis (RA) are chronic inflammatory diseases that share similar inflammatory mechanisms and characteristics. Programmed cell death (PCD) has recently garnered attention for its crucial role in regulating inflammation and maintaining tissue homeostasis, as well as for its potential to link these two diseases. The various forms of PCD--including apoptosis, pyroptosis, and necroptosis--are closely controlled by signaling pathways such as Toll-like receptor 4 (TLR4) /NF-κB and MAPK. These pathways determine cell fate and influence inflammatory responses, tissue destruction, and repair, and they both play important roles in the pathogenesis of RA and periodontitis. In periodontitis, periodontal pathogens such as Porphyromonas gingivalis (P. gingivalis) and its virulence factors, including lipopolysaccharide (LPS), induce pyroptosis and necroptosis in immune cells such as macrophages via the TLR4/NF-κB pathway, which leads to an excessive release of pro-inflammatory cytokines such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α. Concurrently, these pathogens inhibit the normal apoptotic process of immune cells, such as neutrophils, prolonging their survival, exacerbating immune imbalance, and aggravating periodontal tissue destruction. Similarly, in RA synovial tissue, fibroblast-like synoviocytes (FLS) acquire apoptosis resistance through signaling pathways such as the Bcl-2 family, JAK/STAT, and NF-κB, allowing for the consistent proliferation and secretion of matrix metalloproteinases and pro-inflammatory cytokines. Meanwhile, the continuous activation of pyroptotic pathways in neutrophils and macrophages results in the sustained release of IL-1β, further exacerbating synovial inflammation and bone destruction. Notably, dysregulated PCD fosters inter-organ crosstalk through shared inflammatory mediators and metabolic networks. Damage-associated molecular patterns (DAMPs) and cytokines that originate from periodontal lesions can spread systemically, influencing cell death processes in synovial and immune cells, thereby aggravating joint inflammation and bone erosion. By contrast, systemic inflammation in RA can upregulate osteoclastic activity or interfere with the normal apoptosis of periodontal cells via TNF-α and IL-6, ultimately intensifying periodontal immune imbalance. This review highlights the pivotal bridging role of PCD in the pathogenesis of both periodontitis and RA, providing a reference for therapeutic strategies that target cell death pathways to manage and potentially mitigate these diseases.