(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 1,548,996 | 2,212,851 | 70.00% | Paris (Archdiocese) | 2004 | ap2005 |
| 2 | 1,350,000 | 1,800,000 | 75.00% | Strasbourg (Archdiocese) | 2004 | ap2005 |
| 3 | 1,200,000 | 1,735,000 | 69.16% | Lyon (-Vienne) (Archdiocese) | 2004 | ap2005 |
| 4 | 1,060,000 | 1,558,000 | 68.04% | Lille | 2004 | ap2005 |
| 5 | 1,104,000 | 1,441,568 | 76.58% | Arras (, Boulogne, e Saint-Omer) | 2004 | ap2005 |
| 6 | 857,000 | 1,428,881 | 59.98% | Nanterre | 2004 | ap2005 |
| 7 | 600,000 | 1,382,100 | 43.41% | Saint-Denis | 2004 | ap2005 |
| 8 | 800,000 | 1,352,141 | 59.17% | Versailles | 2004 | ap2005 |
| 9 | 966,000 | 1,288,311 | 74.98% | Bordeaux (-Bazas) (Archdiocese) | 2004 | ap2005 |
| 10 | 550,000 | 1,226,961 | 44.83% | Créteil | 2004 | ap2005 |
| 11 | 667,615 | 1,213,846 | 55.00% | Meaux | 2004 | ap2005 |
| 12 | 700,000 | 1,145,598 | 61.10% | Grenoble | 2004 | ap2005 |
| 13 | 791,234 | 1,134,546 | 69.74% | Evry-Corbeil-Essonnes | 2004 | ap2005 |
| 14 | 1,049,000 | 1,134,266 | 92.48% | Nantes | 2004 | ap2005 |
| 15 | 829,000 | 1,103,801 | 75.10% | Pontoise | 2004 | ap2005 |
| 16 | 722,420 | 1,047,000 | 69.00% | Toulouse (-Narbonne-Saint Bertrand de Comminges-Rieux) (Archdiocese) | 2004 | ap2005 |
| 17 | 829,000 | 1,023,447 | 81.00% | Metz | 2004 | ap2005 |
| 18 | 750,000 | 1,012,000 | 74.11% | Nice | 2004 | ap2005 |
| 19 | 944,050 | 1,011,862 | 93.30% | Cambrai (Archdiocese) | 2004 | ap2005 |
| 20 | 670,000 | 1,000,000 | 67.00% | Montpellier (, Lodève, Béziers, Agde, e Saint-Pons-de-Thomières) (Archdiocese) | 2004 | ap2005 |
| 21 | 700,000 | 988,723 | 70.80% | Marseille (Archdiocese) | 2004 | ap2005 |
| 22 | 794,264 | 903,400 | 87.92% | Rennes (, Dol, e Saint-Melo) (Archdiocese) | 2004 | ap2005 |
| 23 | 627,000 | 898,000 | 69.82% | Fréjus-Toulon | 2004 | ap2005 |
| 24 | 688,000 | 857,071 | 80.27% | Aix (-Arles-Embrun) (Archdiocese) | 2004 | ap2005 |
| 25 | 750,000 | 852,685 | 87.96% | Quimper [Cornouailles](-Léon) | 2004 | ap2005 |
| 26 | 680,000 | 841,287 | 80.83% | Rouen (Archdiocese) | 2004 | ap2005 |
| 27 | 685,000 | 766,441 | 89.37% | Beauvais (-Noyon-Senlis) | 2004 | ap2005 |
| 28 | 564,706 | 752,942 | 75.00% | Angers | 2004 | ap2005 |
| 29 | 670,000 | 743,417 | 90.12% | Poitiers (Archdiocese) | 2004 | ap2005 |
| 30 | 655,000 | 713,779 | 91.77% | Nancy (-Toul) | 2004 | ap2005 |
| 31 | 461,000 | 647,833 | 71.16% | Bayeux (-Lisieux) | 2004 | ap2005 |
| 32 | 448,200 | 632,557 | 70.86% | Orléans | 2004 | ap2005 |
| 33 | 364,523 | 623,125 | 58.50% | Nimes (-Uzès e Alès) | 2004 | ap2005 |
| 34 | 500,000 | 622,671 | 80.30% | Annecy | 2004 | ap2005 |
| 35 | 550,000 | 620,763 | 88.60% | Bayonne (-Lescar e Oloron) | 2004 | ap2005 |
| 36 | 600,000 | 606,600 | 98.91% | Vannes | 2004 | ap2005 |
| 37 | 588,600 | 604,266 | 97.41% | Clermont (Archdiocese) | 2004 | ap2005 |
| 38 | 561,212 | 597,522 | 93.92% | Reims (Archdiocese) | 2004 | ap2005 |
| 39 | 442,000 | 575,540 | 76.80% | Saint-Etienne | 2004 | ap2005 |
| 40 | 347,456 | 560,413 | 62.00% | Tours (Archdiocese) | 2004 | ap2005 |
| 41 | 380,000 | 557,024 | 68.22% | La Rochelle (-Saintes) | 2004 | ap2005 |
| 42 | 489,000 | 556,100 | 87.93% | Amiens | 2004 | ap2005 |
| 43 | 500,000 | 550,412 | 90.84% | Besançon (Archdiocese) | 2004 | ap2005 |
| 44 | 500,000 | 545,567 | 91.65% | Bourges (Archdiocese) | 2004 | ap2005 |
| 45 | 520,000 | 544,983 | 95.42% | Autun (-Châlon-sur-Saône-Mâcon-Cluny) | 2004 | ap2005 |
| 46 | 541,323 | 542,373 | 99.81% | Saint-Brieuc (-Tréguier) | 2004 | ap2005 |
| 47 | 390,000 | 541,000 | 72.09% | Evreux | 2004 | ap2005 |
| 48 | 505,000 | 539,664 | 93.58% | Luçon | 2004 | ap2005 |
| 49 | 390,000 | 535,489 | 72.83% | Soissons (, Laon, e Saint-Quentin) | 2004 | ap2005 |
| 50 | 370,000 | 529,000 | 69.94% | Le Mans | 2004 | ap2005 |
| 51 | 350,000 | 515,270 | 67.93% | Belley-Ars | 2004 | ap2005 |
| 52 | 329,408 | 506,782 | 65.00% | Dijon (Archdiocese) | 2004 | ap2005 |
| 53 | 350,000 | 498,523 | 70.21% | Avignon (-Apt, Cavaillon, Carpentras, Orange, e Vaison) (Archdiocese) | 2004 | ap2005 |
| 54 | 400,000 | 480,000 | 83.33% | Coutances (-Avranches) | 2004 | ap2005 |
| 55 | 382,690 | 478,363 | 80.00% | Limoges | 2004 | ap2005 |
| 56 | 340,000 | 436,500 | 77.89% | Valence (, Die, e Saint-Paul-Trois-Châteaux) | 2004 | ap2005 |
| 57 | 285,000 | 407,665 | 69.91% | Chartres | 2004 | ap2005 |
| 58 | 308,000 | 400,000 | 77.00% | Perpignan-Elne | 2004 | ap2005 |
| 59 | 300,000 | 399,000 | 75.19% | Le Havre | 2004 | ap2005 |
| 60 | 290,000 | 390,000 | 74.36% | Périgueux (-Sarlat) | 2004 | ap2005 |
| 61 | 370,000 | 380,952 | 97.13% | Saint-Dié | 2004 | ap2005 |
| 62 | 314,000 | 356,748 | 88.02% | Chambéry (, Saint-Jean-de-Maurienne, et Tarentaise) (Archdiocese) | 2004 | ap2005 |
| 63 | 280,000 | 354,867 | 78.90% | Albi (-Castres-Lavaur) (Archdiocese) | 2004 | ap2005 |
| 64 | 293,012 | 344,721 | 85.00% | Moulins | 2004 | ap2005 |
| 65 | 240,000 | 339,628 | 70.67% | Angoulême | 2004 | ap2005 |
| 66 | 200,000 | 332,566 | 60.14% | Sens (-Auxerre) (Archdiocese) | 2004 | ap2005 |
| 67 | 255,000 | 326,617 | 78.07% | Aire (-Dax) | 2004 | ap2005 |
| 68 | 200,000 | 317,945 | 62.90% | Agen | 2004 | ap2005 |
| 69 | 258,680 | 317,810 | 81.39% | Blois | 2004 | ap2005 |
| 70 | 240,000 | 313,756 | 76.49% | Belfort-Montbéliard | 2004 | ap2005 |
| 71 | 180,000 | 309,952 | 58.07% | Carcassonne | 2004 | ap2005 |
| 72 | 274,000 | 293,912 | 93.23% | Sées | 2004 | ap2005 |
| 73 | 205,612 | 292,131 | 70.38% | Troyes | 2004 | ap2005 |
| 74 | 250,000 | 286,000 | 87.41% | Viviers | 2004 | ap2005 |
| 75 | 275,000 | 285,338 | 96.38% | Laval | 2004 | ap2005 |
| 76 | 255,400 | 263,924 | 96.77% | Rodez (-Vabres) | 2004 | ap2005 |
| 77 | 241,150 | 261,500 | 92.22% | Ajaccio | 2004 | ap2005 |
| 78 | 241,224 | 260,836 | 92.48% | Châlons | 2004 | ap2005 |
| 79 | 250,000 | 250,807 | 99.68% | Saint-Claude | 2004 | ap2005 |
| 80 | 180,000 | 232,000 | 77.59% | Nevers | 2004 | ap2005 |
| 81 | 213,000 | 231,810 | 91.89% | Tulle | 2004 | ap2005 |
| 82 | 150,000 | 222,400 | 67.45% | Tarbes et Lourdes | 2004 | ap2005 |
| 83 | 190,000 | 209,047 | 90.89% | Le Puy-en-Velay | 2004 | ap2005 |
| 84 | 160,000 | 206,034 | 77.66% | Montauban | 2004 | ap2005 |
| 85 | 140,000 | 193,768 | 72.25% | Langres | 2004 | ap2005 |
| 86 | 170,000 | 192,000 | 88.54% | Verdun | 2004 | ap2005 |
| 87 | 152,500 | 172,335 | 88.49% | Auch (-Condom-Lectoure-Lombez) (Archdiocese) | 2004 | ap2005 |
| 88 | 142,900 | 160,124 | 89.24% | Cahors | 2004 | ap2005 |
| 89 | 145,000 | 150,778 | 96.17% | Saint-Flour | 2004 | ap2005 |
| 90 | 110,000 | 139,523 | 78.84% | Digne (-Riez-Sisteron) | 2004 | ap2005 |
| 91 | 99,350 | 138,500 | 71.73% | Pamiers | 2004 | ap2005 |
| 92 | 100,000 | 121,253 | 82.47% | Gap | 2004 | ap2005 |
| 93 | 58,000 | 73,830 | 78.56% | Mende | 2004 | ap2005 |
|