Vector processing engines (VPEs) having programmable data path configurations for providing multi-mode Radix-2X butterfly vector processing circuits. Related vector processors, systems, and methods are also disclosed. The VPEs disclosed herein include a plurality of vector processing stages each having vector processing blocks that have programmable data path configurations for performing Radix-2X butterfly vector operations to perform Fast Fourier Transform (FFT) vector processing operations efficiently. The data path configurations of the vector processing blocks can be programmed to provide different types of Radix-2X butterfly vector operations as well as other arithmetic logic vector operations. As a result, fewer VPEs can provide desired Radix-2X butterfly vector operations and other types arithmetic logic vector operations in a vector processor, thus saving area in the vector processor while still retaining vector processing advantages of fewer register writes and faster vector instruction execution times over scalar processing engines.