This thesis shows the design of a radio frequency photo-injector with a specific requirements for Free Electron Laser. The design is accomplished by using the relevant equations beside SUPERFISH simulation code, which is capable of calculating some of the important parameters necessary for the design. One of the basic ideas in this design is converting the system parameters to an electrical circuit parameters to simplify the design. The photocathode material is copper and it has a cylindrical shape with a radius of 12 mm and quantum efficiency of 10−5 electron per photon. The laser source which illuminates the photocathode is Ti:Sapphire sold state laser with wavelength of 266 nm and pulse energy of 18 mJ. The designed accelerating cavity is a 2½ cell cavity with length of 17 cm and diameter of about 8 cm. The electron bunch charge is 1 nC, and the maximum current per bunch is 1.368 kA, and the extracted electrons has almost zero energy before acceleration, after acceleration, it's energy will be 6.9 MeV. The important engineering and physical considerations were taken in account, the electrical circuit parameters were explained, and the cavity theory and photocathode theory were included.