A key determinant of successful embryo implantation is uterine receptivity. From a non-receptive state during ovulation, this acquisition of receptivity to implantation involves significant molecular and cellular changes in the endometrial lining of the uterus in preparation for the implanting embryo. However, the exact molecular mechanisms underlying this transition remain to be fully characterised. Here, we aimed to generate a comprehensive transcriptome profile of the mouse uterus in the peri-ovulatory and peri-implantation states and characterise transcriptome changes between the two states. Tissue was collected from non-receptive endometrium of estrous C57Bl/6 female mice, and C57Bl/6 females mated to BALB/c males at day 3.5 post-coitum, the day before embryo implantation in mice. High-throughput RNA-sequencing was used to identify the genes and pathways regulated in the endometrium (n=3-4 biological replicates per group). Differential gene expression analysis revealed 546 upregulated and 30 downregulated genes (logFC>1 and adjusted p-value<0.05) in the endometrium of mated mice compared to estrous mice. With the suite of analytical tools from Ingenuity Pathway Analysis, these differentially expressed genes were predicted to activate pathways and upstream regulators involved in implantation, such as the estrogen signalling pathway and vascular endothelial growth factor A. Furthermore, significant molecular changes in the maternal immune and vascular systems occur in the uterus during the pre-implantation phase, as demonstrated by increased functional terms, including leukocyte migration and angiogenesis. Together, our findings confirm that the uterine transcriptome before achieving receptivity is vastly different from the non-receptive estrous uterus, and the changes observed are in line with substantial cellular alterations occurring before embryo implantation. This dataset will serve as a valuable tool and resource for utilisation in future research on the molecular mechanisms of uterine receptivity.