In vitro maturation (IVM) of oocytes retrieved from ovum pick-up (OPU) or ovarian tissue (OT) is a standard approach for patients with specific conditions where prior hormonal stimulation is contraindicated. However, the developmental competence of oocytes matured in vitro is still inferior to that of oocytes matured in vivo. Capacitation-IVM (CAPA-IVM) includes an extra step of pre-maturation culture (PMC) with c-type natriuretic peptide (CNP) as a meiotic arrestor to better synchronize cytoplasmic and nuclear maturity in oocytes. This study aims to evaluate the effect of CAPA-IVM on equine oocyte quality and developmental competence. Immature cumulus-oocyte complexes (COCs) were retrieved from slaughterhouse ovaries and matured in vitro either in CAPA-IVM (short or long) or standard IVM. Matured oocytes from each group were analyzed for calcium-releasing potential and single-oocyte proteomics, and embryo development was assessed after fertilization with Piezo-drilled intracytoplasmic sperm injection (ICSI). Genetic analysis of developed blastocysts was performed to detect chromosomal aberrations. Our findings demonstrate that CAPA-IVM of equine COCs yields significantly higher maturation rates than controls. Moreover, short CAPA-IVM with six hours pre-maturation culture showed substantially higher embryo development potential than the control group. Genetic analysis revealed a high euploidy rate in equine blastocysts regardless of the maturation conditions. Live calcium imaging of the fertilized oocytes demonstrated the majority of oocytes with non-continuous calcium oscillation patterns, irrespective of maturation conditions. Single oocyte proteomics reveals a comparable proteomic landscape between matured oocytes from short CAPA-IVM and standard IVM. However, a trend of differential expression was observed in specific proteins related to cytoskeleton, cell cycle, and hemostasis in the short CAPA-IVM group. Our findings indicate that CAPA-IVM holds the potential to improve oocyte quality and competence in horses. However, further fine-tuning of culture conditions based on omics analysis would benefit the effective use of these IVM systems. Moreover, given that the mare serves as an excellent model for human reproduction, the molecular trends identified in this study could provide valuable insights for advancing human artificial reproductive technologies.