Mil-OSS

{{ more sources | date = March 2023 }}

{{Infobox non-profit

| name = Mil-OSS

| image =

| type =

| founded_date = 2009

| tax_id =

| registration_id =

| founder = Anthony Vela
Joshua L. Davis
John Scott

| location =

| coordinates =

| origins =

| key_people =

| area_served =

| product =

| mission =

| focus = Open-source software in the military

| method =

| revenue =

| endowment =

| num_volunteers =

| num_employees =

| num_members =

| subsid =

| opponents =

| owner =

| non-profit_slogan =

| former name = Military Open Source Software Working Group

| homepage = {{URL|https://mil-oss.dev/}}

| dissolved =

| footnotes =

}}

Mil-OSS, also known as the Military Open Source Software Working Group, is a group that promotes the use and creation of open-source software in the United States Department of Defense.{{cite web|url=http://mil-oss.dev|publisher=Mil-OSS|accessdate=2019-10-21|title=Welcome to Mil-OSS!}}{{cite magazine|url=https://www.wired.com/dangerroom/2010/08/cia-software-developer-goes-open-source-instead/|title=CIA Software Developer Goes Open Source, Instead|first=Noah|last=Shachtman|magazine=Wired|date=2010-08-04|accessdate=2011-12-21}} Mil-OSS is considered a working group of Open Source for America.