James Cook Ayer (May 5, 1818 – July 3, 1878) was the wealthiest patent medicine businessman of his day.

His success in this line was very great, and soon led him to establish a factory in Lowell for the manufacture of his medicinal preparations, which became one of the largest of its kind in the world, and was magnificently equipped.

[2] In addition to his patent medicine business, Dr. Ayer was involved in textile production in Lowell, Massachusetts, with his brother.

They had three children: His son, Frederick Fanning Ayer became a lawyer and philanthropist, and was director or stockholder of many corporations.

[1] The monument at Ayer's gravesite, a life-size marble lion sculpted by Albert Bruce-Joy, is one of the best known at Lowell Cemetery.