Hydrothermal liquefaction (HTL) emerges as an alternative technique for generating energy resources. The use of algae becomes attractive as they represent a promising source of biomass, mitigating the limitations of firstand second-generation feedstocks in bio-oil production. In this context, a study was conducted to investigate the bio-oil production from the alga Kappaphycus alvarezii (KA) under different HTL conditions. The characterization of the alga showed through proximate and chemical analysis that it is a biomass with a considerable carbohydrate content, high ash content, and low lipid content. TGA and FTIR analyses were also performed. The study examined two approaches: direct liquefaction and liquefaction with glycerol as a cosolvent at temperatures of 250 and 300 per cent for 15 and 45 minutes. Ethanol was added as a cosolvent to enable liquefaction under milder temperature conditions and residence time (200 graus Celsius for 15 min). Sugarcane bagasse (BCA) was also used in co-liquefaction to increase process efficiency.HTL of the alga using ethanol as a cosolvent at the temperature resulted in a bio-oil yield of approximately 16.5 per cent by mass, followed by HTL of the KA/BCA (50 per cent) mixture and pure BCA with 12.9 per cent and 6.3 per cent, respectively. A kinetic study of the alga pyrolysis was also conducted, demonstrating that the Coast-Redfend model was the best fit for the degradation curve. Furthermore, ATR analysis and gas chromatography were performed to characterize the bio-oil. It was concluded that the study demonstrated that the alga KA has potential as a feedstock for bio-oil production.