It is shown that there exists a class of vector transforms and vector series expansions that are independent of their scalar counterparts. They are used to simplify the solutions of a class of vector electromagnetic scattering problems. Applications are shown of vector Fourier, Hankel, and Mathieu transforms and series expansions to the formal solutions of scattering by rectangular, circular and elliptical disks and open-ended waveguides. The problems solved are canonical problems; however, more complex problems for applications in microwaves, microstrip integrated circuits, geophysical probing, etc. , can also be solved in a similar fashion.