This index is an appendix to my series of articles in Recusant History (1972-77) and a supplement to Granville Squiers, Secret Hiding-Places (1933). The 177 houses listed below can therefore be divided into three groups. Twenty-eight, of which twenty-two were in Squiers, have been discussed before in Recusant History and are only dealt with briefly here. Another thirty-four are houses where Squiers now needs correcting or amplifying. The remaining 115 are not in Squiers at all but contain (or contained) something definite enough to justify recording. Houses in Squiers on which there is nothing much to add have been omitted here, and so have all but seven of the places listed in Winifred Haward’s two booklets, Secret Rooms of Yorkshire (1956) and Secret Rooms of North-West England (1964). Ninety-five other houses, none of them in Squiers or Haward, have been considered and discarded, either for lack of sufficient evidence or because the ‘hides’ are inauthentic examples of no interest.