Jacob Leander Loose (June 17, 1850 – September 18, 1923) was an American philanthropist and businessman who founded Sunshine Biscuits.

Jacob Loose was born in Greencastle, Indiana on June 17, 1850.

He attended high school in Decatur, Illinois, but dropped out at the age of 16.

At the age of 20, he moved to Kansas, where he opened a dry goods store with his brother in Chetopa.

He partially retired due to an illness in 1919, and died at the couple's summer home in Gloucester, Massachusetts on September 18, 1923.