Poor parental health can influence the development and eventual health outcomes of their offspring. Many studies have detailed the maternal role yet a father’s health requires further examination as his poor nutritional status has also been shown to have negative consequences on fetal development and impact the long-term health of his offspring. The present study examined how preimplantation embryo development was altered by sub-optimal paternal diet, with specific focus on sperm- and seminal plasma-mediated mechanisms. To address this, male mice were fed a diet to model either under (low protein diet (LPD)) or over (high fat/sugar ‘Western’ diet (WD)) nutrition, LPD or WD supplemented with methyl-donors or a control diet (CD) before mating. Embryo development was assessed using in vitro time-lapse imaging of preimplantation embryos which revealed a significant increase in embryo development rates in all experimental groups when compared to CD embryos. Further analysis of the semen revealed a significant number of differentially expressed seminal plasma proteins in all groups (LPD: 13, MD-LPD: 27, WD: 24, MD-WD: 19) when compared to control. This study highlights a role for paternal nutritional status influencing embryonic development and the maternal reproductive tract via changes to his metabolic and reproductive health. These findings demonstrate potential direct (sperm-mediated) and indirect (seminal plasma-mediated) pathways in which a father's poor diet could shape the long-term health of his offspring