•We studied nest selection in Redshanks nesting on grazed and ungrazed saltmarshes.•They nested in the tallest vegetation available, which was limited by grazing.•They chose the grass Festuca rubra to nest in, which increased with grazing.•Even light grazing <0.5 cattle ha−1y−1 caused Redshank to nest in shorter swards.•Nests in short swards face high predation so grazing affects nest habitat quality. The breeding population of Common Redshank Tringa totanus on British saltmarshes has reduced by >50% since 1985, with declines linked to changes in grazing management. Conservation initiatives have encouraged low-intensity grazing of 0.5 cattle ha−1y−1 but even light grazing can lead to high rates of nest mortality. To avoid predators, Redshank nest in patches of tall vegetation, but the effects of grazing on the availability and quality of habitat selected by Redshank remain unclear. We investigated Redshank nest site selection in relation to cattle grazing and asked (a) which nest vegetation conditions do Redshank select and (b) does grazing limit the availability of higher quality nest sites? We characterised vegetation height and composition at nests and control locations on six saltmarshes grazed between 0 and 0.55 cattle ha−1y−1, which falls within or near the UK Environment Agency definition of light grazing. Redshank selected nest locations in the tallest vegetation available (26±13cm with no grazing), but grazing limited the availability of such tall vegetation (11±7cm at 0.55 cattle ha−1y−1). However, Redshank also selected nest locations dominated by the grass Festuca rubra, which increased with higher livestock densities. By causing Redshank to nest in shorter vegetation, but with more of their preferred grass species, grazing presented a trade-off for Redshank. As previous work has shown that nesting in shorter vegetation results in higher nest predation rates, results of this study suggest that even light conservation grazing can result in Redshank nesting in lower quality habitat. Reducing saltmarsh grazing levels below 0.55 cattle ha−1y−1 may therefore increase Redshank populations by maintaining a vegetation structure with patches of F. rubra but with longer sward heights for nesting.