Objective Psychosocial interventions are historically underutilized by cancer caregivers, but support programs delivered flexibly over the Internet address multiple barriers to care. We adapted Meaning‐Centered Psychotherapy for cancer caregivers, an in‐person psychotherapeutic intervention intended to augment caregivers' sense of meaning and purpose and ameliorate burden, for delivery in a self‐administered web‐based program, the Care for the Cancer Caregiver (CCC) Workshop. The present study evaluated the feasibility, acceptability, and preliminary effects of this program. Methods Eighty‐four caregivers were randomized to the CCC Workshop or waitlist control arm. Quantitative assessments of meaning, burden, anxiety, depression, benefit finding, and spiritual well‐being were conducted preintervention (T1), within 2‐weeks postintervention (T2), and 2‐ to 3‐month follow‐up (T3). In‐depth semistructured interviews were conducted with a subset of participants. Results Forty‐two caregivers were randomized to the CCC Workshop. Attrition was moderate at T2 and T3, with caregiver burden and bereavement as key causes of drop‐out. At T2 and T3, some observed mean change scores and effect sizes were consistent with hypothesized trends (eg, meaning in caregiving, benefit finding, and depressive symptomatology), though no pre‐post significant differences emerged between groups. However, a longitudinal mixed‐effects model found significant differential increases in benefit finding in favor of the CCC arm. Conclusions The CCC Workshop was feasible and acceptable. Based on effect sizes reported here, a larger study will likely establish the efficacy of the CCC Workshop, which has the potential to address unmet needs of caregivers who underutilize in‐person supportive care services.