Lake Umatilla

{{Use mdy dates|date=February 2025}}

{{Infobox body of water

| name = Lake Umatilla

| image = Lake Umatilla....JPG

| caption =

| image_bathymetry =

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| location = Oregon / Washington

| coords = {{coord|45|43|3|N|120|41|38|W|type:waterbody_region:US|display=inline,title}}

| type = reservoir

| inflow = Columbia River

| outflow = Columbia River

| catchment =

| basin_countries = United States

| date-flooded = {{Start date|1971}}

| length = {{convert|110|mi|km|0|abbr=on}}

| width =

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| shore =

| elevation = {{convert|81|m|abbr=on|order=flip}}

| islands =

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| pushpin_map = Oregon#Washington#USA

| pushpin_label_position = bottom

| pushpin_map_alt = Location of Lake Umatilla in Oregon and Washington, USA.

| pushpin_map_caption =

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}}

Lake Umatilla is a {{convert|110|mi|km|0|adj=on}} long{{GNIS|1513298|Lake Umatilla}} reservoir on the Columbia River in the United States, on the border of the U.S. states of Washington and Oregon. It was created in 1971 with the construction of John Day Dam, and stretches upstream to the McNary Dam. It lies in parts of Sherman, Gilliam, Morrow, and Umatilla counties in Oregon, and Klickitat and Benton counties in Washington.