Doctor Who Guest Stars

Which episode did the following guest stars appear and which character did they play?

1. Simon Callow
   
2. Pauline Collins
   
3. Kylie Minogue
   
4. Marc Warren
   
5. Derek Jacobi
   
6. Ardal O’Hanlon
   
7. Simon Pegg
   
8. Sophia Miles
   
9. Anthony Head
   
10. Susannah Constantine
    
11. Maureen Lipman
    
12. Barbara Windsor
    

Answers