is a census-designated place (CDP) in Jefferson County, Washington, United States. The population was 1,968 at the 2000 census. Originally a logging and sawmill community, its economy declined during the first half of the 20th century. Following the completion of the nearby Hood Canal Bridge in 1960, Port Ludlow became the site of resorts and planned communities, attracting more affluent residents who were retired, buying vacation homes, or were making the then more convenient commute to the business centers on the east side of Puget Sound. Based on per capita income, one of the more reliable measures of affluence, Port Ludlow ranks 16th of 522 areas in the state of Washington to be ranked. It is also the highest rank achieved in Jefferson County. Port Ludlow's location and marina facilities make it a convenient and popular port for leisure craft sailing between Puget Sound and the San Juan Islands.
United States Navy Commander Charles Wilkes led an expedition to Puget Sound in 1842 and named
after Navy Lieutenant Augustus C. Ludlow. English-speaking explorers commonly named sheltered inlets they identified in the Pacific Northwest with names beginning with "Port" and the communities which subsequently developed there would adopt the name of that inlet, with the name for the inlet eventually changed to distinguish it from that of the community. Thus the original "Port Ludlow" is now called "Port Ludlow Bay" and the name of the community is "Port Ludlow."
The first shipments of timber from the Puget Sound to San Francisco, California in 1851 stimulated interest in the business potential of building sawmills on Puget Sound. John R. Thorndike and W. P. Sayward sailed to Puget Sound in 1852 and found the environs of Port Ludlow promising. Thorndike filed a timber claim of and they started building a mill there. The initial mill housed two sash saws capable of producing of lumber daily. The trees along the banks of the bay were logged first and then oxen and horses were used to bring more distant logs to the mill. The mill was leased in 1858 to the Amos & Phinney Company, of which A. Phinney became the resident manager.
The U.S. Federal Census of 1860 designated Port Ludlow as one of the three enumeration districts in Jefferson County, Washington Territory. The census tally portrays the make-up of a young logging and sawmill community: Of the 124 people counted, 117 (94%) were adults between the ages of 20 and 50, and the remaining 7 were children. Of the adult population 112 (96%) were men and only 5 women, of which 3 were residing with husbands. 53 (47%) of the men were listed as lumbermen and 14 (13%) as sawyers. Of the total population, 94 (76%) were born in the United States, and of those all were born in the eastern half of the nation but two — a two-year-old born in California and a one-year-old born in Washington Territory. Of the 30 (24%) who were foreign-born, 8 were born in England, 8 in Ireland, 6 in Canada, 4 in Germany, 2 in Norway, and one each in Australia and Denmark. The indigenous peoples were not counted in the 1860 census.