A liquid ejection head, comprising: a first head unit (11b, 11d, 11f, 11h); a second head unit (11a, 11c, 11e, 11g) disposed adjacent to the first head unit (11b, 11d, 11f, 11h) in a first direction, the second head unit (11a, 11c, 11e, 11g) located on a first side of the first head unit (11b, 11d, 11f, 11h) in a second direction orthogonal to the first direction; and a heat uniforming unit (71, 72; 171, 172) shared by the first head unit (11b, 11d, 11f, 11h) and the second head unit (11a, 11c, 11e, 11g), the first head unit (11b, 11d, 11f, 11h) and the second head unit (11a, 11c, 11e, 11g) each comprising: a unit body comprising an actuator configured to cause ejection of liquid from a plurality of nozzles; and a first driver integrated circuit disposed on the first side of the unit body in the second direction, the first driver integrated circuit being configured to drive the actuator, the heat uniforming unit (71, 72; 171, 172) comprising a first heat uniforming member (71; 171) disposed on the first side of the first head unit (11b, 11d, 11f, 11h) and the second head unit (11a, 11c, 11e, 11g) in the second direction, the first side and a second side being opposite sides of the first head unit (11b, 11d, 11f, 11h) in the second direction, wherein the first heat uniforming member 71; 171) comprises a base wall disposed on the first side of the second head unit (11a, 11c, 11e, 11g) in the second direction, the base wall being in thermal contact with the first driver integrated circuit disposed on the second head unit (11a, 11c, 11e, 11g), characterized in that, the first heat uniforming member (71; 171) comprises a first protrusion located next to the second head unit (11a, 11c, 11e, 11g) in the first direction, the first protrusion protruding toward the first head unit (11b, 11d, 11f, 11h) in a direction directed from the first side toward the second side of the first head unit (11b, 11d, 11f, 11h) in the second direction, and the first protrusion comprising a connection wall extending from the base wall toward the first head unit (11b, 11d, 11f, 11h) and a head-unit opposed wall connected to the connection wall and opposed to the first head unit (11b, 11d, 11f, 11h), the head-unit opposed wall being in thermal contact with the first driver integrated circuit disposed on the first head unit (11b, 11d, 11f, 11h). a first head unit (11b, 11d, 11f, 11h); a second head unit (11a, 11c, 11e, 11g) disposed adjacent to the first head unit (11b, 11d, 11f, 11h) in a first direction, the second head unit (11a, 11c, 11e, 11g) located on a first side of the first head unit (11b, 11d, 11f, 11h) in a second direction orthogonal to the first direction; and a heat uniforming unit (71, 72; 171, 172) shared by the first head unit (11b, 11d, 11f, 11h) and the second head unit (11a, 11c, 11e, 11g), the first head unit (11b, 11d, 11f, 11h) and the second head unit (11a, 11c, 11e, 11g) each comprising: a unit body comprising an actuator configured to cause ejection of liquid from a plurality of nozzles; and a first driver integrated circuit disposed on the first side of the unit body in the second direction, the first driver integrated circuit being configured to drive the actuator, a unit body comprising an actuator configured to cause ejection of liquid from a plurality of nozzles; and a first driver integrated circuit disposed on the first side of the unit body in the second direction, the first driver integrated circuit being configured to drive the actuator, the heat uniforming unit (71, 72; 171, 172) comprising a first heat uniforming member (71; 171) disposed on the first side of the first head unit (11b, 11d, 11f, 11h) and the second head unit (11a, 11c, 11e, 11g) in the second direction, the first side and a second side being opposite sides of the first head unit (11b, 11d, 11f, 11h) in the second direction, wherein the first heat uniforming member 71; 171) comprises a base wall disposed on the first side of the second head unit (11a, 11c, 11e, 11g) in the second direction, the base wall being in thermal contact with the first driver integrated circuit disposed on the second head unit (11a, 11c, 11e, 11g), characterized in that, the first heat uniforming member (71; 171) comprises a first protrusion located next to the second head unit (11a, 11c, 11e, 11g) in the first direction, the first protrusion protruding toward the first head unit (11b, 11d, 11f, 11h) in a direction directed from the first side toward the second side of the first head unit (11b, 11d, 11f, 11h) in the second direction, and the first protrusion comprising a connection wall extending from the base wall toward the first head unit (11b, 11d, 11f, 11h) and a head-unit opposed wall connected to the connection wall and opposed to the first head unit (11b, 11d, 11f, 11h), the head-unit opposed wall being in thermal contact with the first driver integrated circuit disposed on the first head unit (11b, 11d, 11f, 11h).