Dementia represents a major global public-health challenge, burdening patients, families, caregivers, and healthcare systems. Advances in generative artificial intelligence (AI)—especially large language models—offer new possibilities, from earlier and more accurate detection to personalized daily-living support. This entry maps the current landscape of generative AI in dementia, showing how it complements traditional discriminative analytics across clinical care (early detection, progression monitoring, treatment planning) and caregiving and communication (conversational agents, caregiver aids, personalized reminiscence, and cognitively engaging tools). This entry also examines the ethical, legal, and social implications of deploying these technologies, including data privacy, informed consent, algorithmic fairness, and system transparency. To translate promise into practice, four technical hurdles must be addressed: multimodal integration, privacy-aware long-term memory, safety under unpredictable inputs, and seamless interoperability with existing health infrastructure. Overcoming them will enable domain-tuned models, caregiver training simulators, personalized prevention coaches, and synthetic data engines that expand scarce datasets without compromising confidentiality. Equitable impact will depend on multilingual mobile tools and governance frameworks that mandate human oversight and continuous auditing. Developed within a person-centered ethic, generative AI has the potential to become a trusted ally—empowering individuals living with dementia, supporting their caregiving networks, and streamlining clinical decision-making.