Martyrologium Romanum Flori-Legium

Acta Sanctorum

Achatius (Acacius), Bishop of Melitene
Achatius the Confessor (of Melitene), Bishop of Hither, Martyr (?)
Adrian, martyr in Greece, venerated on April 16
Agapitus I, Pope
Alexander, Patriarch of Alexandria (anniversary of death)
Ammon, Abbot in the Thebaean Desert
Anicetus, Bishop of Rome, (martyr)
Anthusa, daughter of Emperor Constantine V Kopronymos, nun in Constantinople
Ardalion, Martyr
in the Order of carmelites and discalced Carmelites: Baptista Spagnoli, monk, priest
Basilissa, undertaker of Peter and Paul (?), martyr, and Anastasia, undertaker of Peter and Paul (?), martyr († c. 62)
Benedikta, mother of Alphius, Philadelphius, and Cirinus, martyr
Bernhard, monk in Vallers-la-Ville, Dulder, cf. 20 August
Brynolf Algotsson, Bishop of Skara, poet (Day of Canonization)
Callistus, martyr, and Charisius, martyr, and 7 companions, martyrs
Cogitosus, Bishop (laying of bones in Tours)
Domninus, martyr, perhaps identical to Domnius, Bishop of Salona, martyr
Donanus, abbot of Buchan, now in Aberdeenshire, Scotland († in the 11th century)
Donnanus (Donnan, Dounan) of Eigg, monk / abbot in the Hebrides, martyrs, and 52 companions, monks, martyrs († 616/618)
Eberhard von Wolfegg, Provost in Obermarchtal
Elias of Córdoba, priest, martyr, and Paul, martyr, and Isidore, martyr in Spain
for Paul and Isidore: Diocesan Calendar of Córdoba
Eleutherius, Bishop of Rome, clearly identical to Eleutherius, Bishop of Illyricum, martyr
Eochadus of Lismore and Adam and Lugadius, son of Garvanus, and Lugadius son of the Druchta
Euthymius the Miracle Worker, revered by the Greeks, revered on April 18
Fortunatus, martyr, and Marcian, martyr in Africa or Antioch
Francis Simbronus of Avila, Franciscan religious in the West Indies († 1574)
Gerhard from Breda, Carthusian monk
Gerwin, hermit, abbot in Oudenburg
Gerwin, priest, abbot in Saint-Riquier
Hadulph, Abbot of St. Vedastus in Arras, Bishop of Arras and Cambrai († 728)
Helenus, abbot in Egypt, and Paul, abbot of 500 monks in Libya
Henry Heath, priest, monk, martyr († 1643)
Hermann, the German, monk, founder of the monastery
Honorata, nun (transfer of bones)
Hyacinth of Poland (Hyacinth Odrowaz), Monk (Day of Canonization)
Innocent, Bishop of Tortona
Irene, martyr in Greece († 258), venerated on April 16
Isidora, martyr, and Neophyta, her sister, martyr in Lentini
Jacob of Cerqueto, religious, priest
Jovita, perhaps iderntisch with Jovita, deacon, martyr, and 3 other decapitated companions
Katharina Tekakwitha, penitent
Klara Gambacorti, Prioress in Pisa, and in the Dominican Order: Maria Mancini, Nun
Landricus (Landrich), Bishop of Metz, Abbot of Soignies and Hautmont
Leobaria, martyr => Benedicta, and Jolana, virgin
Leonides, martyr, and Chariessa (Carissa), martyr, and Nica, martyr, and Galena (Galina), martyr, and Calis (Callis), martyr, and Nunecia, martyr, and Basilissa, martyr, and Theodora, martyr
Majolus, Abbot in Cluny
Mappalicus, martyr, and several companions, martyrs, namely: Barucus (Bassus), martyr, and Quintus, martyr, and Victoricus (Victorinus), martyr, and Donatus, martyr, and Januarius, martyr, and Macorus, martyr, and Gallus, martyr, and Theodora, martyr , and Julian's priest, martyr, and Meceonus, martyr, and Miginus, martyr, and Diomedes, martyr, and Filippianus, martyr, and fortunion (Fortunio), martyr, and Credula, martyr, and Firmus, martyr, and Ventus (Venustus), Martyrs, and Fructus, Martyrs, and Martialis, Martyrs, and Ariston, Martyrs
Mary of Christ, Abbess of the Poor Clares Monastery in Fuensalida near Toledo († 1538)
Mary Anna of Jesus Navarro de Guevara y Romero, mystic, tertiary
Marian the Scotsman, historian, cf. 30 January
Max Joseph Metzger, priest, founder
Neophytus, first bishop of Lentini, confessor
Nikephoros, martyr
nameless Franciscan religious in the area around Tortosa († 1584)
Pantagathus, Bishop of Vienne (475 - 540)
Parthenius, martyr, venerated on May 19
Paul of St. Magdalene, Franciscan religious in London, martyr († 1643)
in the Diocese of Oviedo: Pedro Poveda Castroverde, priest, founder of the order, martyr
Peter, deacon, martyr, and Hermogenes, servant, martyr in Antioch († around the 4th century)
Potentiana (Potentienne), Virgin in Spain († in the 7th century)
Potentianus, Bishop of Sens, martyr (transfer of bones)
Rabodo, canon, premonstratensian religious in the monastery of Parc near Leuven,
Regina von Ostrevant, benefactor, founder of the monastery (raising the bones)
Robert, founder of the monastery, abbot of La Chaise-Dieu
Robert of Cîteaux (of Molesme), Abbot of Molesme and Cîteaux (transfer of bones)
Rudolf von Bern, child, martyr
Sabas the Goth, martyr
New Year's Eve (Sevestre, Sevêtre) by Réome, second abbot of Moutier-Saint-Jean near Montbard in Brittany († around 625), venerated on 15 April
Simeon Barsabae, Bishop of Seleucia and Ctesiphon, Metropolitan of Persia, martyr, cf. 21 April, and Abdellas (Abedechalas), priest, martyr, venerated on 21 April, and Khusdazat (Usthazanes), martyr, see below as Khusdazat, venerated on 21 April, and Phusec (Pusei), martyr, and 1150 companions, martyrs, venerated on 21 April, and James, priest, martyr, venerated on 22 April, and Azes (Azadanes, Aza, Azadenes, Azadames), deacon, martyr under King Shapur, venerated on April 22
Stephan Harding, Abbot of Cîteaux
Tancha, virgin, martyr (transfer of bones)
Thomas Cantelupe, Bishop of Hereford (transfer of bones)
Usthazades, eunuch, martyr, and companions, martyrs († 341)
Vasius (Vaise, Vaize), Bishop of Saintes, martyr († 490), venerated on 16 April
Villicus, Bishop of Metz from 543 to 568 († 568), and Arnoald (Arnual), Bishop of Metz
Waltfrid, abbot of Monteverdi Marittimo in Tuscany († c. 765), venerated on 15 February
Wando, Abbot in Fontenelle

Protestant:

Louis de Berquin, Martyr (EKD)
Max Joseph Metzger, priest, founder (EKD)

Orthodox:
in the Julian calendar Kalender - 17. April - Ökumenisches Heiligenlexikon is today the 4th of April

Adrian the Boy, martyr in Corinth († 251), cf. 16 April Catholic
Achatius (Acacius), Bishop of Melitene
Agapitus I, Pope
Alexander, Abbot of Svir († 1533) (collection of bones in 1641)
Anicetus, Bishop of Rome
Bakhazes
Ephrem Didi (the Great) (of Matshqwereli), Bishop of Azquri (Georgia)
Ioann Prigorovskij, priest of Krasnoyarsk, martyr († 1918)
Konstantin von Yekaterinburg, Hieroschemamönch (anniversary of death, † 1960)
Makarios Notaras, Archbishop of Corinth, founder of the monastery
Michael Novitsky, archpriest, confessor († 1935)
Moses
Paisius, Fool for Christ from the Caves near Kiev († 1893)
Patapios, monk, and Thomas, monk, and companions
Simeon, Bishop of Persia, martyr, and Abdechalas (Habdelai), priest, martyr, and ananios, priest, martyr, and Khusdazades (Usphazanes), martyr, and pusei (Phusikos, Fusicus, Pusicius), martyr, and Azates, the eunuch, martyr, and Askritea (Ascitrea), martyr, and 1250 princess, martyr († 344)
Simeon, monk
Theodor Nedosekin, priest of Moscow, martyr († 1942)
Zosima, abbot in Solovki († 1478), and Sabbatius, monk in Solovki