Obadiah Benton McFadden (November 18, 1815 – June 25, 1875) was an American attorney and politician in the Pacific Northwest.

[2] In 1853, Franklin Pierce sent McFadden to Oregon with a commission making Matthew P. Deady a justice of the Territorial Supreme Court.

[2] In 1861, he would become the president of the Washington Legislature's Council Chamber and would serve on that body until 1864 representing Thurston, Lewis and Chehalis counties.

[2] McFadden, Margaret, and their children settled in Chehalis, Washington in 1859, purchasing a 320-acre (130 ha) parcel from the Saunders family who were founders of the city, known as Saundersville at the time.

McFadden died in Olympia on June 25, 1875, and after a large funeral attended by approximately 1,200 people and a regal procession that included a band and carriages, was buried at the Masonic Cemetery.