We report the first demonstration of a slow light laser oscillator. The slow light laser was realized by incorporating an ultra-narrow bandwidth long-delay and low loss transmission filter into an Er/Yb doped fiber laser. We show that the spectral linewidth, free spectral range, relaxation resonance and Relative Intensity Noise (RIN) of a slow light laser are dramatically altered. The modified slow light laser noise dynamics can be explained by the increased cavity photon lifetime due to the filter delay. The slow light effectively increased the laser cavity Q and thus dramatically quenched the laser AM and FM noise by a few orders of magnitude.