Intelligent applications using evolutionary algorithms are becoming famous because of their ability to handle any real time complex and uncertain situations. Swarm intelligence, now-a-days has become a research focus which studies the collective behavior existing among the natural species which lives in group. Bacteria Foraging Optimization (BFO) is an optimization algorithm based on the social intelligence behavior of E.coli bacteria. Literature has witnessed the applications of BFO algorithm and the results reported are promising with regard to its convergence and accuracy. Several studies based on distributed control and optimization also suggested that algorithm based on BFO can be treated as global optimization technique. In this chapter, we have focused on the behavior of biological bacterial colony followed by the optimization algorithm based on bacterial colony foraging. We have also explored variations in the components of BFO algorithm (Revised BFO), hybridization of BFO with other Evolutionary Algorithms (Hybrid BFO) and multi-objective BFO. Finally, we have analyzed some applications of BFO algorithm in various domains. © Springer-Verlag Berlin Heidelberg 2015.