A high-efficiency hybrid Brillouin/ytterbium fiber laser (BYFL) is demonstrated using a 41.5-cm-long highly ytterbium-doped fiber and a 10-m-long single-mode optical fiber. The BYFL operates at 1 052.92 nm, and the difference between it and the Brillouin pump (BP) wavelength matches the expected stimulated Brillouin scattering (SBS) Stokes shift. Its output power reaches 70.1 mW, which is more than seven times higher than the seeded BP power. The BYFL has an optical signal-to-noise ratio that is greater than 65 dB and has many potential applications, such as in controllable optical delay lines, sensing, and RF photonics.