John Commingers Ainsworth (June 6, 1822 – December 30, 1893) was an American pioneer businessman and steamboat owner in Oregon. A native of Ohio, he moved west to mine gold in California before immigrating to Oregon where he piloted steamships and became a founder of the Oregon Steam Navigation Company and several banks.
Ainsworth was born in Springboro, Ohio, on June 6, 1822. His parents died while he was 13 years old, so he went to work for his uncle in Farmington, Iowa. They became partners in a business selling goods from boats along the Ohio River, but soon he split from his uncle and bought a store with a partner, which was sold at a good profit after only one year. He married a young woman, Josephine Augusta Kendall, who died fifteen months later. All of this took place before Ainsworth turned twenty.
Ainsworth was not done partnering with his uncle. In 1844 they bought a steamboat and started a successful packet delivery service along the upper Mississippi River. Then the Gold Rush hit in 1849, and he sold his share of the business to go to California. The Gold Rush did not live up to his expectations, so he found a job piloting a steamer on the Willamette River in Oregon.
After selling out, he entered the banking business in 1883 with the Ainsworth National Bank in Portland. In 1892, he started the Central Bank of Oakland. Ainsworth had four children: George, John, Harry and Daisy. Ainsworth was a Freemason, and eventually the third Grand Master of the Oregon Masonic Lodge. After retiring to California he wrote his autobiography. He died near Oakland, California, on December 30, 1893.