I don't recall that the (Thirty-nine) Articles of Religion mention the Antichrist, and this is possibly the most famous of the Reformation era creedal statements.
Where in it is the Papacy described as the antichrist??
Creeds naming the papacy as the Antichrist;
The first written history suggests Arnulf, the archbishop of Reims in the 10th century identified the Papacy as the Antichrist. Later Joachim of Fiore in the 12th century preached the Papacy was the Antichrist. This led to the martyrdom of many Albigenses, Anabaptists, and others who in part embraced his views. And the archbishop Eberhard II in 1240 also related the papacy to the Antichrist. Synopsis of the End Times; A look at the popular beliefs of today by Mike Morrill.
From The Westminster Confession which also with some adjustments became the 1st and 2nd London Baptist Confessions.
Chapter XXV
Of the Church
VI. There is no other head of the Church but the Lord Jesus Christ. Nor can the Pope of Rome, in any sense, be head thereof. but is that Antichrist, that man of sin, and son of perdition, that exalts himself, in the Church, against Christ and all that is called God.
And from the preface to the Canons of Dort;
For this Church being by God’s mighty hand set free from the tyranny of the Romish Antichrist, & from the fearful idolatry of Popery.....
Martin Luther declared, “We here are of the conviction that the papacy is the seat of the true and real Antichrist.” (Aug. 18, 1520). According to The Prophetic Faith of Our Fathers, by LeRoy Froom. Vol. 2., pg. 121.
I shall briefly show that (Paul’s words in II Thess. 2) are not capable of any other interpretation than that which applies them to the Papacy.” According to Institutes of the Christian Religion, by John Calvin.
John Knox concluded that the Papacy was “the very antichrist, and son of perdition, of whom Paul speaks.” The Zurich Letters, by John Knox, pg. 199.
“Whereof it followeth Rome to be the seat of antichrist, and the pope to be very antichrist himself. I could prove the same by many other scriptures, old writers, and strong reasons.” (Referring to prophecies in Revelation and Daniel.)
Works by Cranmer, Vol. 1, pp. 6-7.
“the pretended Vicar of Christ on earth, who sits as God over the Temple of God, exalting himself not only above all that is called God, but over the souls and consciences of all his vassals, yea over the Spirit of Christ, over the Holy Spirit, yea, and God himself...speaking against the God of heaven, thinking to change times and laws; but he is the son of perdition (II Thess. 2).
Roger Williams (1603-1683) (First Baptist Pastor in America):” The Prophetic Faith of Our Fathers, by Froom, Vol. 3, pg. 52.
Cotton Mather (1663-1728) (Congregational Theologian): “The oracles of God foretold the rising of an Antichrist in the Christian Church: and in the Pope of Rome, all the characteristics of that Antichrist are so marvelously answered that if any who read the Scriptures do not see it, there is a marvelous blindness upon them.” According to The Fall of Babylon by Cotton Mather in Froom’s book, The Prophetic Faith of Our Fathers, Vol. 3, pg. 113.
John Wesley (1703-1791) (Methodist): Speaking of the Papacy, John Wesley wrote, “He is in an emphatical sense, the Man of Sin, as he increases all manner of sin above measure. And he is, too, properly styled the Son of Perdition, as he has caused the death of numberless multitudes, both of his opposers and followers... He it is...that exalteth himself above all that is called God, or that is worshipped...claiming the highest power, and highest honour...claiming the prerogatives which belong to God alone.” Antichrist and His Ten Kingdoms, by John Wesley, pg. 110.
A Great Cloud of Witnesses: “Wycliffe, Tyndale, Luther, Calvin, Cranmer; in the seventeenth century, Bunyan, the translators of the King James Bible and the men who published the Westminster and Baptist confessions of Faith; Sir Isaac Newton, Wesley, Whitfield, Jonathan Edwards; and more recently Spurgeon, Bishop J.C. Ryle and Dr. Martin Lloyd-Jones; these men among countless others, all saw the office of the Papacy as the antichrist.” According to All Roads Lead to Rome, by Michael de Semlyen. Dorchestor House Publications, p. 205. 1991.