In this paper, a compressive detection approach for detecting the presence of multiple Frequency Hopping Spread Spectrum (FHSS) signals is introduced. The large bandwidth produced due to hopping between frequency channels makes interception of FHSS signals challenging. Conventional FHSS detection approaches use channelized radiometers which reduce the sampling rate by dividing the entire FHSS hopping frequency range into sub bands. In this paper, we introduce a detection system which compressively observes the entire FHSS hopping range and can detect not only the presence of FHSS signals but also the number of signals present. Theoretical analysis and simulations are provided to compare the performance of the proposed compressive detection system to a channelized radiometer based detection system.