This is a compilation of pore-water and solid-phase data for station HE443/10 in the Helgoland mud area (German Bight, North Sea). The data derive from a multicorer core (HE443/10-2) and a gravity core (HE443/10-3) which were collected during a RV HEINCKE Expedition in 2015 in order to study iron reduction processes that are linked to methane formation and oxidation. Solid-phase geochemical data includes the bulk elemental composition or the sediment as well as sequential extraction data including reactive iron oxides and sulfides. Furthermore, the stable iron isotope composition of dissolved iron and in sequentially extracted Fe pools has been determined.