Samuel Dinsmoor Jr. (May 8, 1799 – February 24, 1869) was an American lawyer, banker, politician, and the 22nd governor of New Hampshire.

Dinsmoor was born in Keene, New Hampshire and graduated from Dartmouth College in 1814.

He studied law and was a legal assistant to Territorial Governor James Miller for several years in Arkansas.

Upon leaving the governorship, Dinsmoor retired from political life, but continued to stay active in his legal and banking interests.

Anne died on July 17, 1849; and he married Catharine Pickman Abbott Fox on May 4, 1853.