Provided are a cellulose acetate fiber and a cellulose acetate fiber molded article which are excellent in water solubility and biodegradability and are small in load onto the natural environment even when allowed to stand still in the environment. The invention provides a cellulose acetate fiber containing cellulose acetate having a total degree of acetyl substitution of 0.4 to 1.3 and a compositional distribution index (CDI) of 2.0 or less as well as a cellulose acetate fiber molded article.