IMPORTANCE Early detection of melanoma is associated with improved patient outcomes. Data suggest that spouses or partners may facilitate detection of melanoma before the onset of regional and distant metastases. Less well known is the influence of marital status on the detection of early clinically localized melanoma. OBJECTIVE To evaluate the association between marital status and T stage at the time of presentation with early-stage melanoma and the decision for sentinel lymph node biopsy (SLNB) in appropriate patients. DESIGN, SETTING, AND PARTICIPANTS This retrospective, population-based study used the Surveillance, Epidemiology, and End Results database of 18 population-based registered cancer institutes. Patients with cutaneous melanoma who were at least 18 years of age and without evidence of regional or distant metastases and presented from January 1, 2010, through December 31, 2014, were identified for the study. Data were analyzed from September 27 to December 5, 2017. EXPOSURE Marital status, categorized as married, never married, divorced, or widowed. MAIN OUTCOMES AND MEASURES Clinical T stage at presentation and performance of SLNB for lesions with Breslow thickness greater than 1 mm. RESULTS A total of 52 063 patients were identified (58.8% men and 41.2% women; median age, 64 years; interquartile range, 52-75 years). Among married patients, 16 603 (45.7%) presented with T1a disease, compared with 3253 never married patients (43.0%), 1422 divorced patients (39.0%), and 1461 widowed patients (32.2%) (P < .001). Conversely, 428 widowed patients (9.4%) presented with T4b disease compared with 1188 married patients (3.3%) (P < .001). The association between marital status and higher T stage at presentation remained significant among never married (odds ratio [