Caspar Crowninshield (October 23, 1837 – January 10, 1897) was a volunteer officer in the Union Army during the American Civil War.

His roommate was Robert Gould Shaw who would go on to be the colonel of the famed 54th Massachusetts Infantry—the first African-American infantry regiment.

The start of the Civil War interrupted his business career as Crowninshield sought out an officer's commission.

He was promoted to major of the 2nd Regiment of Massachusetts Volunteer Cavalry on January 31, 1863, and became lieutenant colonel on March 18, 1864.

[2] On February 21, 1866, President Andrew Johnson nominated Crowninshield for the award of the honorary grade of brevet brigadier general to rank from March 13, 1865.