Marine-derived bioactives represent an emerging frontier as potential therapeutics in the treatment of neuropsychiatric disorders because of their unique chemical structures, diverse mechanisms, and various physiological benefits. This systematic review explores the potential utilization of many marine-derived bioactives as preventives, diagnostics, and therapeutics in the treatment and management of neuropsychiatric disorders (i.e, depression, anxiety, schizophrenia, etc.). All of the compounds discussed exemplify antioxidant, anti-inflammatory, neuroprotective, neurotransmission modulating, and neurogenic effects, aiding in halting pathological processes, such as oxidative stress, inflammation, disrupted neurotransmitter signaling, and impaired neuroplasticity. Omega-3 fatty acids (DHA/EPA), fucoidan, astaxanthin, phlorotannins, and marine peptides are agents accentuated due to their ability to infiltrate the blood-brain barrier, influencing many cognition processes and aiding in synaptic resilience. This review also explores the historical division between neurology and psychiatry, highlighting the increase in neuropsychiatry, resulting in a need for more integrative therapeutic strategies. Additionally, advances in marine biotechnology, such as single-cell genomic and high-throughput screening, are rapidly advancing compound discoveries and clinical translation. Though challenges persist in bioavailability, scalability, and standardization, marine-derived bioactives offer innovative therapeutic strategies for healthcare providers and patients, potentially addressing the subpar clinical care in the mental health field. In efforts to fully implement marine-derived bioactives into clinical care, continued research surrounding marine organisms is imperative to unlock the full potential of the marine as a pharmacological epicenter.