Joseph Ridgeway Taylor Coates (died September 21, 1921) was an American lawyer and politician from Pennsylvania who served as mayor of Chester, Pennsylvania, from 1887 to 1893.

He was an officer in the Pennsylvania Reserves infantry division of the Union Army in the American Civil War and served in some of the key battles of the war.

In 1861 Coates was mustered in as a 1st lieutenant to the 1st Pennsylvania Reserve Regiment, also known as the 30th Pennsylvania Volunteer Infantry, Company C. Recruited out of Chester, Company C was first known as the "Keystone Guards" and then known for a time as the "Slifer Phalanx".

[1] Coates was promoted from 1st lieutenant to captain in 1862 and to Major by brevet in 1864.

He died on September 21, 1921, and was interred at Chester Rural Cemetery.