django model Form. Include fields from related models

A common practice is to use 2 forms to achieve your goal.

• A form for the User Model:

  class UserForm(forms.ModelForm):
      ... Do stuff if necessary ...
      class Meta:
          model = User
          fields = ('the_fields', 'you_want')
  

• A form for the Student Model:

  class StudentForm (forms.ModelForm):
      ... Do other stuff if necessary ...
      class Meta:
          model = Student
          fields = ('the_fields', 'you_want')
  

• Use both those forms in your view (example of usage):

  def register(request):
      if request.method == 'POST':
          user_form = UserForm(request.POST)
          student_form = StudentForm(request.POST)
          if user_form.is_valid() and student_form.is_valid():
              user_form.save()
              student_form.save()
  

• Render the forms together in your template:

  <form action="." method="post">
      {% csrf_token %}
      {{ user_form.as_p }}
      {{ student_form.as_p }}
      <input type="submit" value="Submit">
  </form>
  

Another option would be for you to change the relationship from OneToOne to ForeignKey (this completely depends on you and I just mention it, not recommend it) and use the inline_formsets to achieve the desired outcome.