Jacob Cox was an American landscape and portrait painter in Indianapolis, Indiana. Several of his paintings are in the Morris-Butler House. He is also known for his paintings of Indiana Governors James B. Ray, Noah Noble, David Wallace, Samuel Bigger, Joseph A. Wright, and Henry S. Lane.

Cox was born in Philadelphia and arrived in Indianapolis in 1833 and established a stove, tinware and coppersmith business. One of his first artistic opportunities came when he painted a banner for the presidential campaign of William Henry Harrison in 1840. After that, he began to paint portraits and in 1842 went to Cincinnati to open a studio with John Dunn, a former treasurer of the State of Indiana. After five months, he returned to his business in Indianapolis and continued painting as a sideline, exhibiting annually at the shows of the Cincinnati Art Union. By 1860, he was devoted to art full-time and became well known in Indianapolis for his portraits and landscapes.

Cox was also a teacher with numerous students including William Merritt Chase.