A Haggadah found in the Cairo Genizah, the storeroom of the Ben Ezra Synagogue in Fustat, Old Cairo, Egypt, "is considered the oldest surviving Haggadah" (Malachi Beit-Arie, "How Hebrew Manuscripts are Made", Gold (ed.) A Sign and a Witness. 2000 Years of Hebrew Books and Illuminated Manuscripts [1988] 36). This Haggadah, dating to about the year 1000, is preserved in the Annenberg Research Institute for Judaic and Near Eastern Studies at the University of Pennsylvania (Halper 211).
However, another Haggadah from the Cairo Genizah preserved at the Jewish Theological Seminary may be from roughly the same date:
"Among the manuscript treasures housed in The Library of the Jewish Theological Seminary is a rare haggadah codex, JTS MS 9560. This early manuscript is one of the few surviving examplars of the ancient Palestinian seder rite. That rite disappeared as a result of the dislocations caused by the Crusades, and it was not rediscovered until the manuscript fragments of the Cairo Genizah came to light at the end of the nineteenth century. MS 9560 was probably deposited in that genizah hundreds of years ago.
"Unlike most of the manuscript fragments found in the Cairo Genizah, this haggadah is almost complete. Based on the writing style, it can be dated to the tenth or the first half of the eleventh century. That makes it one of the earliest Hebrew manuscripts written on paper, and quite possibly the oldest surviving haggadah. With its unskilled writing style and idiosyncratic spelling and linguistic usage, the text bears witness to a layman's home ritual. Therefore, MS 9560 is significant for a number of areas of Jewish research" (http://www.jtsa.edu/Library/News_and_Publications/Between_the_Lines/BTL_121.x, accessed 12-06-2108).