How do you request static .html files under the ~/Views folder in ASP.NET MVC?

Another alternate option is to insert an action method in any of the desired controller to serve the html file

public ActionResult MyHtml()
{
    var result = new FilePathResult("~/Views/HtmlPage1.html", "text/html");
    return result;
}

Access the html as http://yoursite/controller/MyHtml. You may extend this action method to accept the html file name as method/querystrign parameter and render the file at run time, e.g something like this.

 public ActionResult MyHtml(string htmlPageName)
 {
      var result = new FilePathResult($"~/Views/{htmlPageName}.html", "text/html");
      return result;
 }

I want to be able to request static .html files which are located in the ~/Views folder.

Well you can. The marked answer is not entirely correct, although it gives a solution.

The reasoning in the marked answer is correct, it is web.config (BlockViewHandler setting to be specific) in the Views folder that prevents the files to be accessed directly. It is there for securing the views in Asp.Net MVC. But if you asked a question about serving these files directly then you likely have a valid reason to do so, like using AngularJS partial views (as in our case) where we do not want to duplicate the views folder with weird names.

So here is a very simple tweak you can do in the web.config file found in the Views folder, without compromising security of your asp.net mvc views. This will secure the .cshtml files as usual but leave your .html files alone.A

Change this

<add name="BlockViewHandler" path="*" verb="*" preCondition="integratedMode"    type="System.Web.HttpNotFoundHandler" />

--to--

<add name="BlockViewHandler" path="*.cshtml" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />

To allow files like js and html in Views folder edit the web.config in views-Folder:

<system.webServer>
<handlers>
  <add name="JavaScriptHandler" path="*.js" verb="*"
     preCondition="integratedMode" type="System.Web.StaticFileHandler" />      
  <add name="HtmlScriptHandler" path="*.html" verb="*"
     preCondition="integratedMode" type="System.Web.StaticFileHandler" />
  <remove name="BlockViewHandler"/>
  <add name="BlockViewHandler" path="*" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />
</handlers>

I want to be able to request static .html files which are located in the '~/Views' folder.

You can't. There's a web.config file in this folder which explicitly forbids accessing any file from it. If you want to be able to access files from the client those files should not be placed in the Views folder which has a special meaning in ASP.NET MVC.

You could have a ~/Static folder where you could place your HTML files. And then access it like that:

http://example.com/yourapplicationname/static/foo.html