The Capt. Seth Baker Jr. House is a historic house in Barnstable, Massachusetts, USA. Built about 1850, it is a late example of transitional Federal-Greek Revival architecture, and a somewhat modest house built for a ship's captain. It was listed on the National Register of Historic Places in 1987.

The Captain Seth Baker Jr. House stands in a busy commercial area of the village of Hyannis, on the south side of Main Street between Parkway Place and Bayview Street. It is a 1+1⁄2-story wood-frame structure, with a side-gable roof, central chimney, and clapboarded exterior. Its front facade is five bays wide, with a central entrance framed by Federal style slender pilasters, tall frieze, and projecting cornice. Greek Revival features include its slightly lower window placement and the clapboarded exterior. A modern single-story addition extends to the rear.

The house was built about 1850, and its survival in what is now a commercial area is a reminder of the area's early history. It was built by Seth Baker, Jr., a deep-sea ship's captain. The house's modest features are a contrast to the more elaborate houses often built by ship's captains in the area, indicating that there was a wide range of economic situations in that profession. The house now houses professional offices.

• National Register of Historic Places listings in Barnstable, Massachusetts