The 2021 Smoky Mountains Computational Sciences and Engineering Conference (SMC2021) is hosting its fifth annual Data Challenge. The SMC2021 Data Challenge provides an opportunity to tackle scientific data challenges that come from eminent data sets at ORNL. These data sets come from scientific simulations and instruments in physical and chemical sciences, electron microscopy, bioinformatics, neutron sources, urban development, and other areas. These data sets will be used for the SMC Data Challenge (SMCDC2021) competition. For more information please visit: https://smc-datachallenge.ornl.gov