Biocrude oil also known as bio-oil or tar is considered as an alternative liquid fuel that can be produced from thermochemical conversion such as hydrothermal liquefaction and pyrolysis of biomass. Bio-oil is primarily produced from abundantly available lignocellulosic biomass (LCB) waste. However, a major impediment to the commercialization of LCB-derived biocrude as a direct transportation fuel is attributed to its poor quality and consequently must be upgraded prior to use. The bio-oil produced from LCB is highly viscous, oxygenated and acidic which is due to the presence of a complicated composition comprising of cellulose, hemicellulose and lignin. Therefore, recent research is directed towards exploring more appropriate biomass to harvest the actual potential of bio-oil as renewable fuel. In this regard, microalgae and oleaginous yeast are prospective source of bio-oil production since algal and yeast cells contain no lignin and lack cellulose. Moreover, the de-oiled cake is a surplus by-product from the microbial biofuel industry which is increasingly being explored for the production of bio-oil and biochar. Further, bio-oils are rich in phenolic derivatives, organic acids and carbonyl compounds which could be responsible for the insecticidal effect and antimicrobial activities. Exploring the potentials of biocrude oil as pesticides and antimicrobial agents would increase the scope for commercialization and enhance the economic viability of the production process. In this chapter, we intend to provide a comprehensive overview on the production of biocrude oil from microalgal and oleaginous yeast biomass using various thermochemical conversion processes. The chapter also discusses the industrial applications of biocrude oil with emphasis on biofuel production and development of pesticides for enhanced commercialization and economic viability of the production process.