Abstract: There is disclosed a window blind suitable for use in arch-type and semi-circle windows, including windows having a curved side defined by a radius, including irregularly shaped windows having a curved side with a varying radius. The apparatus is designed to provide both privacy and shade, and may also be readily opened and closed. A plurality of slats is pivotal in relation to a mounting base or base, and can be deployed into an array to cover the entirety of a semi-circular window. The apparatus features a mounting base, which serves as the foundation for the complete apparatus. The mounting base typically is generally rectilinear, so to be suited for fastened attachment (as by mounting brackets and screws, or the like) to the “flat” or straight side of an arched or roughly semi-circular window. Other principal components of the apparatus include a plurality of slats which are pivotally attached to the mounting base.