Using the following to catch 401's in my app

.config(['$httpProvider', function($httpProvider) {
$httpProvider.interceptors.push(function($q) {
    return {
        'responseError': function(rejection){
            var defer = $q.defer();
            if(rejection.status == 401){
                  $state.go('login', {}, {reload: true, inherit: false});
            }
            defer.reject(rejection);
            return defer.promise;
        }
    };
});
}]);

I know the $state.go won't work as it can't be injected. How do I pull up my login page in this state.

As @Martin wrote, you can inject $state as you inject $q, but as you noted you've got a circular dependency because $state is dependent on $http (to get the views), but now $http configuration is dependent on $state as well.

To break the circle, you can use the $injector service, and manually inject $state after all dependency checks are done:

.config(['$httpProvider', function($httpProvider) {
$httpProvider.interceptors.push(function($q, $injector) { // inject $injector service
    return {
        'responseError': function(rejection){

            var $state = $injector.get('$state'); // manually inject $state service using $injector

            var defer = $q.defer();
            if(rejection.status == 401){
                  $state.go('login', {}, {reload: true, inherit: false});
            }
            defer.reject(rejection);
            return defer.promise;
        }
    };
});
}]);