In vitro generation of functional gametes is a promising approach for treating infertility, although faithful replication of meiosis has proven to be a substantial obstacle to deriving haploid gamete cells in culture. Here we report complete in vitro meiosis from embryonic stem cell (ESC)-derived primordial germ cells (PGCLCs). Co-culture of PGCLCs with neonatal testicular somatic cells and sequential exposure to morphogens and sex hormones reproduced key hallmarks of meiosis, including erasure of genetic imprinting, chromosomal synapsis and recombination, and correct nuclear DNA and chromosomal content in the resulting haploid cells. Intracytoplasmic injection of the resulting spermatid-like cells into oocytes produced viable and fertile offspring, showing that this robust stepwise approach can functionally recapitulate male gametogenesis in vitro. These findings provide a platform for investigating meiotic mechanisms and the potential generation of human haploid spermatids in vitro. Display omitted •Haploid spermatid-like cells (SLCs) were derived by stepwise differentiation of ESCs•This process completely recapitulated meiosis in vitro, meeting meiotic hallmarks•Intracytoplasmic injection of SLCs produced euploid and fertile offspring In vitro production of haploid gametes could provide a treatment for infertility, but recapitulating meiosis in culture is a significant roadblock. Zhou et al. report the generation of haploid male gametes from mouse ESCs that can produce viable and fertile offspring, demonstrating functional reproduction of meiosis in vitro.