In this study, we have developed microalgae immobilized by polysulfone nanofibrous web (microalgae/PSU-NFW) for the removal of reactive dyes (Remazol Black 5 (RB5) and Reactive Blue 221 (RB221). Here, an electrospinning technique was used to produce polysulfone nanofibrous web (PSU-NFW) as a free-standing material on which microalgae Chlamydomona reinhardtii was immobilized on PSU-NFW. The decolorization capacities of microalgae/PSU-NFW were significantly higher than that of pristine PSU-NFW. The decolorization rate for RB5 was calculated as 72.97 ± 0.3% for microalgae/PSU-NFW, whereas it was 12.36 ± 0.3% for the pristine PSU-NFW. In the case of RB221 solution, decolorization rates were achieved as 30.2 ± 0.23 and 5.51 ± 0.4% for microalgae/PSU-NFW and pristine PSU-NFW, respectively. Reusability tests revealed that microalgae/PSU-NFW can be used in at least three successive decolorization steps in which the decolorization rate of the RB5 was found to be 51 ± 0.69% after the third reuse step. These results are promising and therefore suggest that microalgae/PSU-NFW could be applicable for the decolorization of dyes because of their versatility and reusability.