Methanoarchaea, a unique group of archaea, play a crucial role in the global carbon cycle through methanogenesis, a process where different carbon sources such as carbon dioxide (CO2)/hydrogen (H2), acetate, formate, methanol, and methylamines are metabolized and methane is produced. Transposons are mobile genetic elements (MGEs) capable of moving within and between genomes, thus significantly influencing genetic diversity and evolution. This chapter will investigate the presence, diversity, and functional implications of transposons in methanoarchaea. We explore the various types of transposable elements (TEs) identified in methanogenic genomes and highlight their structural and functional characteristics. Our focus is on insertion sequences (IS), miniature inverted-repeat transposable elements (MITEs), and the recently described casposons, which show similarities to eukaryotic transposons, using Cas1 solo as the transposase. Summarizing current knowledge on the diversity, mechanisms, and impacts of TEs in methanoarchaea reveals their significant role in genome plasticity, adaptation to diverse environmental conditions, and potential contributions to horizontal gene transfer (HGT) within microbial communities. Understanding transposons in methanoarchaea not only provides insight into the fundamental processes governing microbial evolution but also offers potential applications in biotechnology and environmental management. This review synthesizes current understanding of archaeal TEs, focusing on their diversity, mechanisms, and evolutionary significance.