During processes such as the formation and regression of follicles and corpora lutea in the adult ovary, the composition of the extracellular matrix (ECM) changes, suggesting distinct roles in these processes. The composition and roles of ECM in fetal ovaries are less well understood. Fetal ovarian development begins with the division of mesenchymal cells on the surface of the posterior abdominal wall near the mesonephros, forming the gonadal ridge. Primordial germ cells (oogonia) migrate into the gonadal ridge and replicate, forming the ovigerous cords from which primordial follicles later develop. We examined the ECM in bovine ovaries from 53 fetuses with crown-rump lengths from 3.2 - 104 cm (63 - 296 days of gestation) by immunohistochemistry and electron microscopy. Ovigerous cords containing oogonia and somatic cells are separated from stroma by a basal lamina (BL) composed of laminin, collagens type IV (alpha 1) and XVIII, perlecan, and nidogens 1 and 2. Stromal areas contain thick fibres positive for fibrillin-1, decorin, versican, fibronectin and collagen type I, and thinner fibres of fibrillin-3, perlecan, nidogens 1 and 2, and collagen type IV. Initially ovigerous cords are open at the ovarian surface. Migration of stromal cells to below the surface coincides with the development of a BL separating a single layer of somatic cells at the surface from the rest of the ovarian tissue. BLs around stromal capillaries and underlying the surface epithelium have the same composition as the BL around ovigerous cords and primordial follicles. In conclusion, we identified a BL between stroma and ovigerous cords that expands into the BL of follicles and below the surface epithelium as the stroma partitions the ovigerous cords into these structures. In addition, we identified that somatic cells within ovigerous cords give rise to the ovarian surface epithelium and the granulosa cells that surround the oocyte.