PurposeWorkplace loneliness has become a concern in diverse work settings. However, workplace loneliness research is in its early stages of development and not much is known about the effects of it on organizations and its members, especially in police organizations. The purpose of this study is to investigate the relationships between workplace loneliness, anxiety, happiness, task performance, and organizational citizenship behavior (OCB). Data from police officers in Korea were used to test these relationships.Design/methodology/approachUsing a three-wave time-lagged procedure, the study sample consisted of 227 police officers in South Korea from one regional police headquarters (Yongin Dongbu Police Station) and four substations in the Yongin region. The study tested parallel mediation of anxiety and happiness in the relationships between workplace loneliness and workplace outcomes using the PROCESS macro (Model 4) for SPSS 26.FindingsThe regression analyses with bootstrapping results indicated that police officers' anxiety and happiness served as mediating mechanisms linking workplace loneliness with task performance and OCB.Originality/valueThe police force is a very significant facet within society. However, research has not yet investigated loneliness in the police context. Thus, the study investigated the proximal and distal effects of workplace loneliness by associating workplace loneliness with task performance and OCB via anxiety and happiness.