Individuals diagnosed with cancer face a host of new and unique challenges following their diagnosis. The prevalence of existential issues such as control, identity, relationships, and meaning are well-documented in existing scientific literature. This article outlines the need and considerations for existential counseling with this population based on existing evidence and suggests that such an approach pairs well with second wave positive psychology. The inclusion of second wave positive psychology acknowledges adversity to promote mature happiness. This approach facilitates effective adjustment and coping to reduce morbidity and improve quality of life for clients diagnosed with cancer. Clients may find meaning in their cancer diagnosis, improving both quality of life and survival. Psychotherapists engaging in this critical work are encouraged to adopt an individualistic, dialectical approach that respects client choice, addresses cognitive avoidance, refrains from pathologizing despair, and is supplemented by cognitive therapy. Future research is needed to confirm benefits and outcomes of existential psychotherapy that incorporates second wave positive psychology.