Mechanosensitive ion channels sense force and pressure in immune cells to drive the inflammatory response in highly mechanical organs. Here, we report that Piezo1 channels repress group 2 innate lymphoid cell (ILC2)–driven type 2 inflammation in the lungs. Piezo1 is induced on lung ILC2s upon activation, as genetic ablation of Piezo1 in ILC2s increases their function and exacerbates the development of airway hyperreactivity (AHR). Conversely, Piezo1 agonist Yoda1 reduces ILC2-driven lung inflammation. Mechanistically, Yoda1 inhibits ILC2 cytokine secretion and proliferation in a KLF2-dependent manner, as we found that Piezo1 engagement reduces ILC2 oxidative metabolism. Consequently, in vivo Yoda1 treatment reduces the development of AHR in experimental models of ILC2-driven allergic asthma. Human-circulating ILC2s express and induce Piezo1 upon activation, as Yoda1 treatment of humanized mice reduces human ILC2-driven AHR. Our studies define Piezo1 as a critical regulator of ILC2s, and we propose the potential of Piezo1 activation as a novel therapeutic approach for the treatment of ILC2-driven allergic asthma.