The claustrum, a subcortical nucleus forming extensive connections with the neocortex, has been implicated in sensory selection. Sensory-evoked claustrum activity is thought to modulate the neocortex’s context-dependent response to sensory input. Recording from claustrum neurons while mice performed a tactile-visual sensory-selection task, we found that neurons in the anterior claustrum, including putative optotagged claustrocortical neurons projecting to the primary somatosensory cortex (S1), were rarely modulated by sensory input. Rather, they exhibited different types of direction-tuned motor responses. Furthermore, we found that claustrum neurons encoded upcoming movement during intertrial intervals and that pairs of claustrum neurons exhibiting synchronous firing were enriched for pairs preferring contralateral lick directions, suggesting that the activity of specific ensembles of similarly tuned claustrum neurons may modulate cortical activity. Chemogenetic inhibition of claustrocortical neurons decreased lick responses to inappropriate sensory stimuli. Altogether, our data indicate that the claustrum is integrated into higher-order premotor circuits recently implicated in decision-making. Display omitted •Anterior claustrum neurons exhibit motor responses•Claustrum neurons, including S1-projecting neurons, encode lick direction•Neuron pairs with synchronous firing during intertrial intervals are similarly tuned•Chemogenetic inhibition of claustrocortical neurons decreases false alarms Chevée, Finkel et al. show that the activity of neurons in the anterior claustrum recorded during a cross-modal sensory selection task reflects movement rather than sensory input. Premotor activity in individual claustrum neurons was biased for ipsilateral or contralateral movements and encoded upcoming lick direction during intertrial intervals.