The salivary glands are exocrine organs that secrete saliva to maintain oral health and homeostasis. Dysfunctional salivary glands exhibit symptoms of dry mouth, including dental caries and dysfunction in speech and swallowing. Current clinical therapies for dry mouth disease include artificial saliva substitutes or parasympathetic stimulants, but these are transient and palliative approaches. To achieve the functional recovery of dysfunctional salivary glands, salivary gland tissue stem cells are thought to be candidate cell sources for salivary gland tissue repair therapies. In addition, whole salivary gland replacement therapy is expected to be a novel therapy resulting in the regeneration of fully functional salivary glands. The salivary glands arise from their organ germs, which are induced by epithelial–mesenchymal interactions. Recently, we developed a novel bioengineering method, that is, the organ germ method, which can regenerate the ectodermal organs, including the teeth, hair, lacrimal glands, and salivary glands. The bioengineered salivary glands successfully secrete saliva into the oral cavity and can also improve the symptoms of dry mouth, such as bacterial infection and swallowing dysfunction. In this review, we summarize recent findings and bioengineering methods for salivary gland regeneration therapy.