The sympathetic nervous system (SNS) controls various physiological functions via the neurotransmitter noradrenaline. Activation of the SNS in response to psychological or physical stress is frequently associated with weakened immunity. Here, we investigated how adrenoceptor signaling influences leukocyte behavior. Intravital two-photon imaging after injection of noradrenaline revealed transient inhibition of CD8+ and CD4+ T cell locomotion in tissues. Expression of β-adrenergic receptor in hematopoietic cells was not required for NA-mediated inhibition of motility. Rather, chemogenetic activation of the SNS or treatment with adrenergic receptor agonists induced vasoconstriction and decreased local blood flow, resulting in abrupt hypoxia that triggered rapid calcium signaling in leukocytes and halted cell motility. Oxygen supplementation reversed these effects. Treatment with adrenergic receptor agonists impaired T cell responses induced in response to viral and parasitic infections, as well as anti-tumor responses. Thus, stimulation of the SNS impairs leukocyte mobility, providing a mechanistic understanding of the link between adrenergic receptors and compromised immunity. Display omitted •Activation of the sympathetic nervous system halts leukocyte locomotion in tissues•Noradrenaline induces adrenergic receptor signaling to reduce lymph node blood flow•Decreased tissue oxygenation induces calcium signaling to control leukocyte motility•Disruption of leukocyte motility contributes to impaired immune responses Activation of the sympathetic nervous system (SNS) in response to psychological or physical stress is frequently associated with weakened immunity. Devi et al. reveal that stimulation of the SNS impairs leukocyte mobility and impairs immune responses, providing a mechanistic understanding of the link between adrenergic receptors and compromised immunity.