Sphingosine-1-phosphate (S1P) is a bioactive lipid that plays a critical role in immune cell function and inflammation resolution. It acts through S1P receptors (S1PRs) to regulate immune responses, including cell trafficking, signaling, and inflammation. S1P is involved in both innate and adaptive immunity, influencing immune cell migration, activation, and communication. S1P levels are tightly regulated by sphingosine kinases (SphKs) and phosphatases, and its concentration gradient is essential for immune cell movement and tissue homeostasis. S1P has been shown to reduce inflammation by modulating immune cell behavior, such as suppressing pro-inflammatory responses and promoting anti-inflammatory signals. S1P also plays a role in maintaining vascular integrity and preventing excessive immune activation. SphK1 and SphK2 have opposing effects on inflammation. SphK1 promotes inflammation by activating pro-inflammatory pathways, while SphK2 has anti-inflammatory effects by inhibiting inflammatory signaling. S1P signaling is crucial for immune cell trafficking, particularly in lymph nodes and secondary lymphoid organs. S1P gradients guide immune cell movement, ensuring proper immune responses and tissue repair. S1P receptor modulators, such as FTY720, siponimod, and ozanimod, are being developed as therapeutic agents for inflammatory and autoimmune diseases. These drugs target specific S1PRs to modulate immune responses, reduce inflammation, and improve disease outcomes. S1P is involved in various inflammatory conditions, including sepsis, autoimmune diseases, and chronic inflammation. Its role in immune cell trafficking and signaling makes it a promising target for therapeutic intervention. Research on S1P signaling has revealed its importance in immune homeostasis and disease progression. Future studies aim to further elucidate the mechanisms of S1P in immune responses and develop targeted therapies for inflammatory diseases. S1P signaling modulation offers a potential strategy for treating a wide range of inflammatory and autoimmune conditions.Sphingosine-1-phosphate (S1P) is a bioactive lipid that plays a critical role in immune cell function and inflammation resolution. It acts through S1P receptors (S1PRs) to regulate immune responses, including cell trafficking, signaling, and inflammation. S1P is involved in both innate and adaptive immunity, influencing immune cell migration, activation, and communication. S1P levels are tightly regulated by sphingosine kinases (SphKs) and phosphatases, and its concentration gradient is essential for immune cell movement and tissue homeostasis. S1P has been shown to reduce inflammation by modulating immune cell behavior, such as suppressing pro-inflammatory responses and promoting anti-inflammatory signals. S1P also plays a role in maintaining vascular integrity and preventing excessive immune activation. SphK1 and SphK2 have opposing effects on inflammation. SphK1 promotes inflammation by activating pro-inflammatory pathways, while SphK2 has anti-inflammatory effects by inhibiting inflammatory signaling. S1P signaling is crucial for immune cell trafficking, particularly in lymph nodes and secondary lymphoid organs. S1P gradients guide immune cell movement, ensuring proper immune responses and tissue repair. S1P receptor modulators, such as FTY720, siponimod, and ozanimod, are being developed as therapeutic agents for inflammatory and autoimmune diseases. These drugs target specific S1PRs to modulate immune responses, reduce inflammation, and improve disease outcomes. S1P is involved in various inflammatory conditions, including sepsis, autoimmune diseases, and chronic inflammation. Its role in immune cell trafficking and signaling makes it a promising target for therapeutic intervention. Research on S1P signaling has revealed its importance in immune homeostasis and disease progression. Future studies aim to further elucidate the mechanisms of S1P in immune responses and develop targeted therapies for inflammatory diseases. S1P signaling modulation offers a potential strategy for treating a wide range of inflammatory and autoimmune conditions.