The invention relates to a liquid ejection head. The liquid ejection head includes a substrate having an ejection opening through which a liquid is ejected, a recessed member having a wall defining arecess in which the substrate is disposed away from the wall with a gap therebetween, and a sealing member filling the gap. The sealing member includes a cured product of a composition containing a first polyol compound, an isocyanate compound having an isocyanate group, and a second polyol compound that is more reactive with the isocyanate group than the first polyol compound.