David Dwight Baldwin was born November 26, 1831 in Honolulu. His father was early missionary doctor Dwight Baldwin (1798–1886), and his mother was Charlotte Fowler Baldwin (1805–1873). After a few years living in Waimea, the family moved to the island of Maui around 1837. From 1841 through 1851, Baldwin attended Punahou School in Honolulu, and graduated from Yale in 1857. He married Lois Gregory Morris (1837–1924) on October 7 of that year at Bridgeport, Connecticut. The couple returned to the Kingdom of Hawaii in 1858, and had nine children, although one died young.
From 1860 to 1862 Baldwin served in the Kingdom House of Representatives. Around 1865 he became manager of the sugarcane plantation in Kohala on the northern coast of Hawaiiʻi Island. This plantation had been founded by the missionary Elias Bond.
In 1872 Baldwin and his family lived in New Haven, Connecticut while he worked in the Yale Law School library and earned his Master of Arts degree. On his return to Hawaii he started an almost 40-year association with the education department of the Hawaiian government. He was vice-principal of Lahainaluna School from 1874 to 1877. While he was inspector-general of the schools from 1877 to 1885, instruction was changed from the Hawaiian language to English. Baldwin returned to Lahainaluna and served as vice-principal again until 1890.
In 1890 he moved to Haʻikū where his younger brother Henry Perrine Baldwin (1842–1911) had founded the agricultural venture Alexander & Baldwin with his brother-in-law Samuel Thomas Alexander (1836–1904). He organized a small school for the plantation employees. Baldwin had earlier published a list of Hawaiian mosses and liverworts (hepatic plants, or Hepaticae in Latin).

Rest in Peace David :)