DNA endoreplication has been implicated as a cell strategy to grow in size and in tissue injury. Here, we demonstrate that barrier to autointegration factor (BAF), represses endoreplication in Drosophila myofibers. We show that BAF localization at the nuclear envelope was eliminated either in mutants of the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, in which the LEM-domain protein Otefin was similarly excluded, or after disruption of the nucleus-sarcomere connections. Furthermore, BAF localization at the nuclear envelope required the activity of the BAF kinase VRK1/Ball, and consistently non-phosphorytable BAF-GFP was excluded from the nuclear envelope. Importantly, removal of BAF from the nuclear envelope correlated with increased DNA content in the myonuclei. E2F1, a key regulator of endoreplication was found to overlap BAF localization at the myonuclear envelope, and BAF removal from the nuclear envelope resulted with increased E2F1 levels in the nucleoplasm, and subsequent elevated DNA content. We suggest that LINC-dependent, and phospho-sensitive attachment of BAF to the nuclear envelope, through its binding to Otefin, tethers E2F1 to the nuclear envelope thus inhibiting its accumulation at the nucleoplasm.