Ovarian cancer survival rates remain at 40% due to late stage disease at diagnosis. The current treatment regimens of cytoreductive surgery and carboplatin/paclitaxel chemo therapy have not changed in the past thirty years and women often experience cancer recurrence. Therefore, there is an important need for molecular biomarkers and targeted therapies to improve patient outcome. The overall aim of this thesis was to explore the role of Wnt receptors ROR1 and ROR2 in ovarian cancer and investigate their potential as new therapeutic targets. This thesis was produced as a series of publications that contribute to each chapter. This research demonstrated an abnormal upregulation of ROR1 and ROR2 in both ovarian tumour (publication 1) and associated ovarian cancer stroma (publication 3) compared to patient samples from benign ovarian conditions. Patients with upregulated ROR2 had an association with higher grade (publication 1) and upregulation of both ROR1 and ROR2 in the stroma correlated with worse PFS and OS (publication 3). In vitro studies using a siRNA approach in an HGSOC cell line OVCAR3 revealed functional roles of ROR1 and ROR2 in migration and invasion. Moreover, silencing both receptors simultaneously greatly inhibited the ability of ovarian cancer cells to proliferate and spread (publication 1). A subsequent assessment of ROR1/2 expression in an in vitro model of chemoresistant ovarian cancer (using parental HGSOC cell line A2780 and cisplatin resistant A2780-cis) showed upregulation of both receptors. Silencing ROR1/2 in this model also reduced ovarian cancer cell proliferation, migration and invasion and sensitised them to cisplatin (publication 2). Finally, an organotypic 3D model of ovarian cancer metastasis to the omentum was used to validate the previous studies and found that ROR depleted cells were less able to adhere and invade into the model (publication 4). This thesis showed an important combined role of ROR1 and ROR2 in epithelial ovarian cancer progression. Current clinical trials using anti-ROR1 therapy should be extended to ovarian cancer patients with advanced disease and also provides evidence to create anti-ROR2 therapies. Therapeutic targeting of ROR1 and ROR2 in metastatic disease may represent a potential treatment for patients who currently are limited to chemotherapy and may develop chemoresistant disease.