Iruma River

{{Redirect|Irumagawa|the sumo coach|Tochitsukasa Tetsuo}}

{{Infobox river

| name = Iruma River

| native_name ={{native name|ja|入間川}}

| image = Iruma River Kazi Bridge Tx-re.jpg

| image_size = 200px

| image_caption = Iruma River in Hannō, Saitama

| source1_location = Mount Hannō in Hannō, Saitama

| subdivision_type1 = Country

| subdivision_name1 = Japan

| length_km = 63

| source1_elevation = {{convert|1197|m|ft|abbr=on}}

| mouth_location = Arakawa River

| mouth_elevation =

| discharge1_avg =

| basin_size_km2 = 721

}}

The {{nihongo|Iruma River|入間川|Iruma-gawa}}, is a river in Saitama Prefecture, Japan.{{Cite journal |last=Group |first=Sasai Fossil Forest Research |date=1984 |title=Geology of the Sasai Fossil Forest in the Bedrock of Iruma River, Saitama Prefecture, Japan. |url=https://cir.nii.ac.jp/crid/1571135649123259264 |journal=Bull Saitama Mus Nat |volume=2}}{{Cite web |title=災害・防災情報：令和元年台風第19号による被害状況等について - 国土交通省 |url=https://www.mlit.go.jp/saigai/saigai_191012.html |access-date=2022-11-29 |website=www.mlit.go.jp}} It is {{convert|63|km}} long and has a watershed of {{convert|721|km2}}.

The river rises from Mount Ōmochi in Hannō, Saitama and flows to the Arakawa River at Kawagoe, Saitama.