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The observed stellar luminosity function (SLF) of field stars near the Sun is probably the most basic of data concerning stars in the Galaxy; the SLF is defined as the number of stars per cubic parsec within an absolute magnitude interval M; ± bM; where j denotes either bolometric or a specific bandpass and typically bM; = 0.5 mag. It forms the basis for calculating the observed mass densities for a variety of stars thus enabling the deri· vation of the total observed stellar mass densities for comparison with dynamically derived mass densities. It is also used to reconstruct the initial mass function (IMF) for faint stars and to explore the star formation history of the disk and halo. It is of great interest to measure stellar luminosity functions for different subgroups of stars: for main sequence stars with different metallicities, for degenerate white dwarfs, and for globular clusters, open clusters, and active star forming regions (T·associations). Comparison of these lumin· osity functions provides information about many different aspects of astronomy such as star formation scenarios, stellar evolution, cooling theories of white dwarfs, the evolution of stellar populations in galaxies, and the formation of galaxies by the disruption of clusters. In this review we summarize the most recent measurements of the SLFs below Mv = 5; this regime includes hydrogen burning main sequence stars with masses between � 0.08 M 0 and I M 0, substellar objects with masses below the mimimum main· sequence mass (i.e. the brown dwarfs, hereafter