Microorganisms are essential associates for virtually all arthropod species. Insect-associated microbes can improve the fitness of their host, be pathogens, or have no known role. During the past decade, we have increased our collective knowledge of the composition of insect-associated microbes along with the range of roles that these symbionts perform. Increases in knowledge are partly due to the continued advancements in genomic sequencing technologies. This understanding of individual microbe contributions and advancements in sequencing have allowed for a shift towards examining the complexity of microbial communities, as well as how these communities vary with different factors (e.g., microbe and/or host genetics, environment). We provide an overview of arthropod-symbiont interactions, the variety of symbiont functionalities, and the evolutionary ecology of these relationships. Additionally, we explored the influence of the environment on the modulation of insect-microbe interactions, the projected impacts of climate change, and the subsequent consequences on these ecological interactions. Lastly, we discuss some potential avenues for the future of arthropod-microbe interactions that include the modification of existing microbial symbionts as well as the construction of synthetic microbial communities. Our aim was to condense the current knowledge on insect-associated microbes and microbial communities while discussing research gaps and challenges for possible future directions.