A sewing machine frame includes a pillar frame and an extending frame. The extending frame extends from one end in a longitudinal direction of the pillar frame, in an extending direction orthogonal to the longitudinal direction. The extending frame includes a first extending plate, a second extending plate, and an extending intermediate plate. The first extending plate extends in the extending direction. The second extending plate is separated from the first extending plate in the longitudinal direction. The second extending plate faces the first extending plate and extends in the extending direction. The extending intermediate plate extends in the longitudinal direction and the extending direction. The extending intermediate plate couples the first extending plate and the second extending plate in the longitudinal direction, and the extending intermediate plate has a curved surface.