Insomnia is highly prevalent among older adults, and hypnotics are widely prescribed in Japan. As older individuals are vulnerable to hypnotic-related adverse events, such as falls and cognitive impairment, monitoring national prescription trends is essential for safer pharmacotherapy. Using the National Database Open Data from fiscal years 2019–2023, we examined nationwide prescription trends of hypnotics indicated for insomnia (or insomnia with pre-anesthetic medication). We calculated the annual total dispensed quantity, the dispensed quantity attributable to adults aged ≥65 years, and the proportion (%) of dispensed quantity among older adults. Conventional hypnotics (benzodiazepines and Z-drugs) and newer agents, including dual orexin receptor antagonists (DORAs), were evaluated. Zolpidem remained the most frequently used hypnotic, increasing from 506 million dispensed dosage units in 2019 to 685 million in 2023. However, the proportion of dispensed quantity attributable to adults aged ≥65 years declined from 64.7% to 60.2%. Brotizolam exhibited a similar utilization trend, with stable overall use but a reduction from 66.6% to 62.1% in the older adult population. In contrast, lemborexant, introduced in 2020, demonstrated a rapid uptake, reaching 504 million dispensed dosage units in 2023, whereas its proportion of use among older adults increased from 38.9% to 51.1%. Insomnia medication prescription trends are shifting in Japan, with the increasing adoption of DORAs along with a relative decline in conventional hypnotics among older adults. Continued monitoring is warranted to support safer prescription practices in geriatric insomnia care.