Current information technology relies on two independent processes: charge-based information processing (microprocessors) and spin-based data storage (magnetic hard drives).([1-5]) The prospect of simultaneously manipulating both charge and spin in a single semiconductor medium is provided by the exciting area of spintronics. Among many others, diluted magnetic semiconductors (DMSs) represent the most promising candidates for such applications. ([1-7]) Herein we report on the magneto- and optoelectronic properties of single-crystalline diluted magnetic semiconductor nanowires Ga1-xMnxN (x=0.01-0.09). These nanowires, which have diameters of similar to 10-100 nm and lengths of up to tens of micrometers, exhibit ferromagnetism with Curie temperatures (T(C)s) above 300 K and magnetoresistances (MRs) up to 250 K. Spin-dependent electron transport from single-nanowire transistors indicates the homogeneous nature of the ferromagnetic nanowires.