In the present review, we discuss the proton-sensing mechanisms, focusing on proton-sensing ionotropic receptors, such as transient receptor potential vanilloid-1 (TRPV1) and acid-sensing ion channels (ASICs), and metabotropic ovarian cancer G protein-coupled receptor 1 (OGR1)-family G protein-coupled receptors (GPCRs), in the airway inflammation and AHR in asthma and respiratory diseases. Here, GPR68 is linked to asthma.