Potential small-scale discrepancies in the picture of galaxy formation painted by the Lambda CDM paradigm have led to considerations of modi fied dark matter models. One such dark matter model that has recently attracted much attention is fuzzy dark matter (FDM). In FDM models, the dark matter is envisaged to be an ultra-light scalar field with a particle mass m(FDM) similar to 10(-22) eV. This yields astronomically large de Broglie wavelengths which can suppress small-scale structure formation and give rise to the observed kpc-sized density cores in dwarf galaxies. We investigate the evolution of the 21-cm signal during Cosmic Dawn and the Epoch of Reionization (EoR) in Lambda FDM cosmologies using analytical models. The delay in source formation and the absence of small halos in Lambda FDM significantly postpone the Ly alpha coupling, heating, as well as the reionization of the neutral hydrogen of the intergalactic medium. As a result, the absorption feature in the evolution of the global 21-cm signal has a significantly smaller full width at half maximum (Delta z less than or similar to 3), than Lambda CDM (Delta z similar or equal to 6). This alone rules out mFDM < 6 x 10(-22) eV as a result of the 2 sigma lower limit Delta z greater than or similar to 4 from EDGES High-Band. As a result, Lambda FDM is not a viable solution to the potential small-scale problems facing Lambda CDM. Finally, we show that any detection of the 21-cm signal at redshifts z > 14 by interferometers such as the SKA can also exclude Lambda FDM models.