<p>The widespread presence and persistence of microplastics (MPs) and nanoplastics (NPs) pose significant ecological and human health risks, particularly in disrupting endocrine systems, which are vital to maintain the metabolic balance. This systematic review summarizes 15 primary research articles retrieved from the SCOPUS database based on inclusion and exclusion criteria, examining the effects of these plastics on endocrine functions in various models, including human placental tissue (<i>n</i> = 1), male mice (<i>n</i> = 3), female mice (<i>n</i> = 7), zebrafish (<i>Danio rerio</i>) (<i>n</i> = 3), and trout (<i>Oncorhynchus mykiss</i>) (<i>n</i> = 1). The majority of studies focused on polystyrene particles (<i>n</i> = 14), with polyamide also examined (<i>n</i> = 1). Notable findings reveal that exposure to MPs and NPs causes endocrine disruptions primarily due to oxidative stress, leading to thyroid and reproductive hormone imbalances, ovarian dysfunction, and fertility issues. These disruptions have widespread impacts on metabolism, growth, development, and behaviour across the studied models, underscoring the profound implications of MP and NP contamination on biological systems. Overall, this review presented a crucial area for future research and urgency to mitigate the effects of plastic pollution on human and environmental health.</p>