Trichoderma reesei is a filamentous fungus long known for its secretory capacity, finding applications across several industries. The selection of a member from this genus, in particular, is no coincidence Trichoderma are globally distributed, and therefore were some of the first well-studied fungal species. Integral to their success is the application of hydrophobins - small molecular weight proteins with high surface activity. Characterising and cataloging the diversity of these proteins across the Trichoderma genus benefits research in novel medical and industrial applications, as well as our biological understanding of mycoparasitism. Thus, an acute need to develop more efficient hydrophobin production platforms exists. Alongside cataloging the diversity of hydrophobins across the Trichoderma genus, overexpression models allow more realistic industrial-level yields to be achieved. In an effort to design a T. reesei based production system, two plasmids containing class II hydrophobin genes from T. virens were transformed into a T. reesei host. These hydrophobins were the well-known HFB4, and the recently discovered HFB7. Framing the gene of interest is a constitutive promoter, chosen to maximise secretory capacity, as well as a histidine tag for purification. As HFB4 is present in both species, it was hypothesised that T. reesei would produce a functionally identical HFB4 as in the native T. virens. The resulting overexpression mutants were therefore considered to be homologous expression systems. Proteins lacking in the parental species genome are more unpredictable, as the organism may struggle to produce or overexpress an identical protein. For this reason, the HFB7 overexpression mutants are considered to be a heterologous expression system. The T. reesei hydrophobin overexpression mutants produced during the current study are of interest for continuing research, which should further characterise the overexpressed proteins to determine how they differ from those produced in cell factories based on other organisms. Fundamentally, this study provides a stepping stone into the use of T. reesei as a host organism for hydrophobin production at an industrial scale.