A new slotted rectangular waveguide array antenna is introduced, which is constructed on the conformal cylindrical surface. Unlike other slotted waveguide arrays, this array has a beam with a large tilt angle from the broadside of the linear array. The array consists of a waveguide with inclined slots cutting in the narrow wall and a matching load at one end for the traveling wave operation. The antenna is designed and built using the analytical procedure combining with the commercial software. The radiation patterns and gain of the antenna are measured, and the experimental data obtained are compared with the theoretical results.