This paper provides an overview of biopsychosocial components of sexuality in older adults, sexual expression in older LGBTQ and cognitively impaired adults, and inappropriate sexual behaviors (ISBs) in dementia. Sexual expression of older adults is influenced by diverse psychosocial and biologic determinants including ageist beliefs. Although the prevalence of sexual dysfunction increases with age, studies of sexual satisfaction reveal that only a minority experience significant distress. Stigma against sexual expression in LGBTQ older adults may cause concealment of sexual orientation from family or care providers due to fears of rejection. Cognitive impairment affects frequency of and satisfaction with sexual activity, as well as capacity to consent. Staff biases about sexuality can negatively impact sexual expression in healthcare settings. Dementia-related inappropriate sexual behaviors (ISBs) are common and distressing. Recent research has focused on early identification and prevention of ISB, in addition to management through non-pharmacologic and pharmacologic approaches. Sexuality remains integral to quality of life for many older adults and informed consideration of their needs is critical to healthcare delivery and institutional service planning. A comprehensive understanding of older adults' sexuality can enhance education, research, policy, and clinical care for this growing population.