Host-guest inclusion complexes represent the simplest example of a supramolecular system, in which a small “guest” molecule becomes included within the interior cavity of a larger, cage-like “host” molecule. This inclusion can have a number of significant effects on the physical and spectroscopic properties of the guest. One particularly useful effect is the significant enhancement of the guest fluorescence, which occurs for a wide range of guests, for a variety of reasons. If the guest is an analyte of interest, then this inclusion-induced fluorescence enhancement provides a simple, convenient means to significantly increase the sensitivity of its fluorescence-based trace analysis. This article will provide a comprehensive review of the recent application of host-guest inclusion to the spectrofluorimetric trace analysis of a wide range of guests of interest, including pharmaceutical and environmentally important compounds, in a variety of hosts, including cyclodextrins and calixarenes.