Offshore wind energy has been identified as one of the most promising and increasingly attractive sources of energy. This technology offers a long-term power-generation source, less environmental impact, and fewer physical restrictions. However, given the complexity of this technology, economic feasibility studies are essential. Thus, this study aims to identify the main trends and criteria or the methods used in the economic feasibility studies of offshore wind energy, providing a review of the state of the art in this literature. For this, a Systematic Literature Review was carried out. The article shows the growing interest in offshore wind power generation and highlights how recently the interest in the studies that assess the technical–economic feasibility of this source has grown; it presents the main milestones of the topic. Based on a structured literature review, this article identifies the main trends in this topic: (i) wind farms, (ii) risk, (iii) floating offshore wind farms, (iv) decommissioning and repowering, (v) net present value, (vi) life cycle cost, and (vii) multi-criteria decision-making; it provides a broad view of the methodological possibilities and specificities for investors and researchers interested in conducting studies on the economic feasibility of offshore wind generation. In addition, finally, a research agenda is proposed.