The Synod of Laodicea and the OT Canon

 

"The canon list of Synod of Laodecia agrees with the twenty-two books of the Jewish canon except that it includes Baruch and the Epistle of Jeremiah together with Jeremiah as the twentieth book. The Synod of Laodecia included Esther, and it excluded the deuterocanonical books.....[fn. 287] - The Old Testament section does not include the deuterocanonical books" (Edmon L. Gallagher and John D. Meade, The Biblical Canon Lists from Early Christianity: Texts and Analysis, pg. 131)

Canon 59 - "No psalms composed by private individuals nor any uncanonical books may be read in the church, but only the Canonical Books of the Old and New Testaments."

Canon 60 - "These are all the books of Old Testament appointed to be read: 1, Genesis of the world; 2, The Exodus from Egypt; 3, Leviticus; 4, Numbers; 5, Deuteronomy; 6, Joshua, the son of Nun; 7, Judges, Ruth; 8, Esther; 9, Of the Kings, First and Second; 10, Of the Kings, Third and Fourth; 11, Chronicles, First and Second; 12, Esdras, First and Second; 13, The Book of Psalms; 14, The Proverbs of Solomon; 15, Ecclesiastes; 16, The Song of Songs; 17, Job; 18, The Twelve Prophets; 19, Isaiah; 20, Jeremiah, and Baruch, the Lamentations, and the Epistle; 21, Ezekiel; 22, Daniel.And these are the books of the New Testament: Four Gospels, according to Matthew, Mark, Luke and John; The Acts of the Apostles; Seven Catholic Epistles, to wit, one of James, two of Peter, three of John, one of Jude; Fourteen Epistles of Paul, one to the Romans, two to the Corinthians, one to the Galatians, one to the Ephesians, one to the Philippians, one to the Colossians, two to the Thessalonians, one to the Hebrews, two to Timothy, one to Titus, and one to Philemon."

(https://www.newadvent.org/fathers/3806.htm)

To be fair, there is dispute as these canons' authenticity, especially since this canon was not included in the version of Dionysius Exiguus.  However, there are good reasons nonetheless to accept them as genuine.

"However, the canon list could be authentic to the actual proceedings of the synod since (1) it agrees with many of the Eastern lists from the fourth century; and (2) Dionysius was probably motivated to omit the Eastern list of books because he had already included the papal letter of Innocent I in his collection of western canon law, which included the wider biblical canon for the church of Rome." (Gallagher and Meade, The Biblical Canon Lists from Early Christianity: Texts and Analysis, pg. 131)

Plus, canon 59 says that only the canonical books should be read by Christians. This obviously entails an understanding of what those books are, and thus a canon list of books would make perfect contextual sense as the next canon right after. 

Roman Catholic church historian Charles Hefele admits that the canon is most likely authentic:

"Such an omission [of the deuterocanonical books] is, however, the less remarkable, as it is known that in the fourth century it was the custom even among the Fathers of the Church (for instance, Athanasius), to reckon in the catalogue of the Holy Scriptures only the proto-canonical, and not the deuterocanonical books....A special treatise concerning the genuineness of this canon was published by Spittler in 1777, in which he seeks to show that it did not emanate from the Synod of Laodicea, but was only added later, and taken from the eighty-fifth Apostolic Canon. His principles reasons are :--- a) That Dionysius has not this canon in his translation of the Laodicean decrees. It might, indeed, be said with Dallaeus and Van Espen, that Dionysius omitted this list of the books of Scripture because in Rome, where composed this work, another by Innocent I. was in general use....But Schrock at least, even if somewhat hesitatingly, has raised the objection, that if this Synod in its 59th canon ordered that only the canonical books should be read, an explanation was obviously needed as to which are the canonical books. To this I may further add, first, that the Laodicean Canon of Scripture and that of the Canones Apost. are by no means identical, as Spittler assumes, but differ essentially both in the Old and New Testament; secondly, that the two argumenta ex silentio which Spittler alone employs in favour of his assertion, namely, the silence of Dionysius, John of Antioch, and Martin of Braga, are not in my opinion sufficient to outweigh the many manuscripts and quotations which support the sixtieth canon. And that only fifty-nine Laodicean canons are cited by many of the ancient Fathers proves nothing for Spittler, because, as he himself states, in very many old manuscripts the fifty-ninth and sixtieth canons were written as one, as the latter does in fact belong to the former." (Charles Hefele, A History of the Councils of the Church, vol. 2, pgs. 323-325)