Tauwharenīkau River

{{Use New Zealand English|date=April 2024}}

{{Use dmy dates|date=July 2019}}

{{Infobox river

| name = Tauwharenīkau River

| image = Tauherenikau River 12.jpg

| image_size =

| image_caption =

| source1_location = Mount Hector

| mouth_location = Lake Wairarapa

| subdivision_type1 = Country

| subdivision_name1 = New Zealand

| length = {{convert|41|km|mi|abbr=on}}

| source1_elevation =

| mouth_elevation =

| discharge1_avg =

| basin_size =

}}

The Tauwharenīkau River, formerly known as the Tauherenikau River, is a river of the Wellington Region of New Zealand's North Island. It flows initially southeast from its sources on the slopes of Mount Hector before turning southwest to run down a long valley in the Tararua Range. From the end of the valley it again turns southeast, flowing past the town of Featherston before reaching the northern shore of Lake Wairarapa.

On 7 March 2023, the name of the river was officially altered to Tauwharenīkau River, following the enactment of the Ngāti Kahungunu ki Wairarapa Tāmaki nui-a-Rua Claims Settlement Act 2022.{{cite web |url=https://www.linz.govt.nz/our-work/new-zealand-geographic-board/recent-place-name-decisions/nzgb-notices-march-2023 |title=NZGB notices – March 2023 |publisher=New Zealand Geographic Board |access-date=11 June 2023}}