SIMC 2021 is a biennial event organized by the Strathmore Institute of Mathematical Sciences. The theme is "Advancing Research and Education in Mathematical Sciences in the Big data Era" The conference will be organized around the following five strands: Pure Mathematics; Mathematical modeling; Data Science/Statistics; Mathematics Education; Mathematical Finance/Economics. The first two days (28th and 29th June) will be committed to pre-conference schools in the five strands. The three conference days (June 30-July 2nd) will be organized around plenary and parallel sessions in the five strands.