The invention provides modulators of the nociceptin receptor (NOP), including both agonists and antagonists. A compound of the invention can be a selective modulator of NOP with respect to the μ- and κ-opioid receptors (MOP and KOP), thus providing a therapeutic method for the treatment of conditions wherein selective NOP modulation is medically indicated and MOP or KOP modulation may be less desirable. A compound of the invention can be a NOP full agonist, partial agonist, inverse agonist, positive or negative allosteric modulator, or a functionally biased agonist. A compound of the invention can be used for the treatment of an anxiety state, post-traumatic stress disorder, addictive disorders (including overuse of alcohol, tobacco, and drugs of abuse such as cocaine, amphetamines, and opitates), misregulated food intake and/or energy expenditure, cough, sleep disorders, migraine, pain, depression, or neurodegenerative disorders such as Parkinsons disease or Alzheimers disease.