Convert Newtonsoft.Json.Linq.JArray to a list of specific object type

Just call array.ToObject<List<SelectableEnumItem>>() method. It will return what you need.

Documentation: Convert JSON to a Type

The example in the question is a simpler case where the property names matched exactly in json and in code. If the property names do not exactly match, e.g. property in json is "first_name": "Mark" and the property in code is FirstName then use the Select method as follows

List<SelectableEnumItem> items = ((JArray)array).Select(x => new SelectableEnumItem
{
    FirstName = (string)x["first_name"],
    Selected = (bool)x["selected"]
}).ToList();