Most of the links below are to GoogleBooks, although you will also find a few links to other digital library projects online, too. If you find a marvelous online Aesop edition somewhere that you are enjoying, please let me know!
The item in bold corresponds to the reference abbreviation in the notes to the fables:
Abstemius. Abstemii Fabulae, in Mythologia Aesopica, edited by Isaac Nicolas Nevelet, 1610. (online)
Ademar of Chabannes. Fabulae Antiquae expositae ab Ademaro Cabannensi, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Aelian. De Natura Animalium (Latin translation), Friedrich Jacobs. 1832. (online)
Ahn, Franz. Short Latin Course. 1883. (online)
Alciato. Alciati Emblematum liber, 1621. (online)
Andrews, Ethan Allen. First Lessons in Latin. 1856. (online)
Aphthonius. Aphthonii Fabulae, in Mythologia Aesopica, edited by Isaac Nicolas Nevelet, 1610. (online)
Aramaic fables. Fabulae Aliquot Aramaeae, ed. Julius Landsberger, 1846. (online)
Avianus. Fabulae Aniani, Guilielmo Hermanno interprete, in Aesopi Phrygis et aliorum fabulae. 1560. (online)
Babrius. Babrii Fabulae Iambicae CXXIII, ed. Jean François Boissonade, 1844. (online)
Barlow, Francis. Aesop's Fables. 1687. (online)
Bernae Romuleae et Diversae Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Bozon. Nicolai Bozon Exempla in Latinam translata, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 4, 1896. (online)
Camerarius, Joachim. Fabulae Aesopicae, 1579. (online)
Clarke, H. Select Fables of Aesop, 1810. (online)
Collar, William C. Via Latina: An Easy Latin Reader. 1897. (online)
Dana, Joseph. Liber Primus, or A First Book of Latin exercises. 1824. (online)
Daumas. Fabellae Aesopicae Quaedam Notiores, ed. Christianus Daumus. 1724. (online)
De Furia. Fabulae Aesopicae, ed. Franciscus De Furia, 1810. (online)
De Vitry. The Exempla or Illustrative Stories from the Sermones Vulgares of Jacques de Vitry, ed. Thomas F. Crane. 1890. (online)
Desbillons, François-Joseph. Fabulae Aesopiae. 1778. (online)
Dio Chrysostom. Dionis Chrysostomi Orationes LXXX, Latin translation by Thomas Naogeorgus. 1604. (online)
Directorium Humanae Vitae, ed. Vittorio Puntoni. 1884. (online)
Eton Aesop. Aesopi Fabulae Graeco-Latinae: Eton, 1769. (online)
Evans, John. First Lessons in Latin. 1823. (online)
Faernus. Gabrielis Faerni Fabulae Centum, 1793. (online)
Fénelon. Fabulae Selectae Joannis de La Fontaine, in Lettres et Opuscules Inédits, 1850. (online)
Gallup, Frank A. A Latin Reader. 1913. (online)
Gildersleeve, Basil. Latin Reader. 1875. (online)
Giraud, J.B. Fabulae Selectae Fontanii in Latinum Sermonem Conversae. Vol. 1-2. 1775. (online)
Gradatim. Heatley, H.R. and H.N. Kingdon. Gradatim: An Easy Latin Translation Book for Beginners. 1884. (online)
Heidelberg, H. Lateinische Uebungs- und Lesebuch. 1873. (online)
Irenaeus, P. Mithologica Sacro-Profana, seu Florilegium Fabularum. 1666. (online)
Jacobs, Frederic and Frederic William Doering. The Latin Reader. 1857. (online)
Liber Kalilae et Dimnae, ed. Alfons Hilka. 1928. (online)
Life of Aesop. Aesopi Vita, in Mythologia Aesopica, edited by Isaac Nicolas Nevelet, 1610. (online)
Luqman. Locmanni Fabulae, ed. T. Erpenius. 1636. (online)
Mantuanus. Apologus ex Mantuano traductus in Aesopi et aliorum fabulae. 1802. (online)
Medieval Promptuarium, in Die fabeln der Marie de France, ed. M. Niemeyer. 1898. (online)
Moore, Frank Gardner. Porta latina: Fables of La Fontaine in a Latin version. 1915. (online)
Morris, Charles D'Urban. A Latin Reading-Book. 1873. (online)
Munich Romulus. Monachii Romuleae et Extravagantes Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Nequam (Alexander Neckham). Novus Aesopus, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Odo (1): Fables (with appendices). Odonis de Ceritona Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 4, 1896. (online)
Odo (2): Parables. Odonis de Ceritona Parabolae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 4, 1896. (online)
Phaedrus (1). Fabulae Aesopiae, ed. L. Mueller. 1903. (online)
Phaedrus (2): Perotti's Appendix, in Phaedri Fabulae Aesopiae, ed. C. T. Dressler, 1838. (online)
Poggio Bracciolini. Facetiarum. 1592. (online)
Potts, A.W. and C. Darnell. Aditus Faciliores. 1875. (online)
Romulus Anglicus (1). Romuli Anglici Cunctis Exorta Fabulae cum Appendice, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Romulus Anglicus (2): Appendix. Romuli Anglici Nonnullis Exorta Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Romulus Breviatus. Romuli Vulgaris Breviatae Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Romulus Florentinus, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Romulus Rhythmicus, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Romulus, ed. Hermann Oesterley. 1870. (online)
Romulus: Vienna. Romuli Vindobonensis Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Sheppey. Johannis de Schepeya Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 4, 1896. (online)
Spencer, J.G. Scalae Primae: A First Latin Reader. 1908. (online)
Steinhowel. Steinhowels Aesop, ed. Hermann Oesterley. 1873. (online)
Stoddart, George Henry. The New Delectus. 1848. (online)
Syntipas (Michael Andreopoulos). Syntipae philosophi persae fabulae, ed. C.F. Matthaeus. 1781. (online)
Thomas, A.H. First Latin Translation Book. 1902. (online)
Vincent of Beauvais. Vincentii Bellovacensis Romuleae Fabulae, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Walter of England (prose). Gualterianae Fabulae in solutam orationem, in Les Fabulistes Latins, edited by Leopold Hervieux, Volume 2, 1894. (online)
Yenni, D. A Grammar of the Latin Language. 1869. (online)