I found this resource  that lists all the references to Genesis found in the New Testament, and it made me curious if there is a list of all Old Testament quotes found in the New Testament. Have you come across any such list?
No authoritative answer to this question can be given, because New Testament authors did not explicitly mark all the places where they quoted or alluded to the Old Testament. Indeed, many of them probably would not have been able to do so even if they tried, since they had internalized the Old Testament text so thoroughly, and thus they adopted its language as their own.
As a result, researchers have broken down New Testament uses of the OT into categories like "direct quotation," "indirect quotation," "allusion," and "possible allusion," and, not surprisingly, they disagree on what fits into each category. So in the end, no two lists are the same.
That said, there are still some helpful resources that begin to tackle the question. The first one I'll mention is a free project from the Blue Letter Bible, "Parallel Passages in New Testament Quoted from Old Testament," which has the following goal:
The list contains not only the direct or indirect citations, but also the allusions which are particularly worthy of attention
Thus it will not necessarily contain all the quotes/allusions, just ones considered particularly noteworthy. A quick analysis of this list gives the following totals:
- Quotes: 302
- Allusions: 493
- Possible allusions: 138
- Total: 933
The second resource, a more in-depth one, is the book Commentary on the New Testament Use of the Old Testament, edited by Beale and Carson. It works through the entire New Testament, calling out many parallels between the NT and OT texts. Depending on your locale, you may be able to preview parts of this work for free on Google Books.
One final caveat: Besides the aforementioned difficulty in compiling such a list, both of the resources mentioned here come from Protestant sources, and thus will not typically take note of references to any deuterocanonical books recognized as part of the Old Testament by Catholics and Eastern Orthodox. Thus if such references are also desired, these sources will be incomplete in that respect as well.
This question is somewhat of an anachronism, as the New and Old testaments were not compiled until about 400 AD. At the time the events of the New testament took place, some volumes of scripture in common use were the Tanakh, and the Septuagint. These were some of the works that Jesus and the disciples referenced.
There are over 200 references made in the New Testament to scriptures, prophecies and writings of the prophets, lists of these references can be found from multiple sources online, but there are other writings referenced in the New Testament that no longer exist, such as some prophecies of Enoch, which were known to Jude (Jude 1:14-15).
There are numerous references in the Old Testament as well to "lost books".
If you want to get a sense of how many cross-referable verses there are in the New Testament, you can use a resource such as this one.
The site of R. Grant Jones, whose purpose is to show the preference for the Septuagint (LXX) text over the Masoretic text in NT quotations of the OT, provides a list of all such quotations, in NT order:
The text of the quotes, also in NT order, can be found on another site:
Grant Jones provides also a table which gives the total number of quotations of the whole OT and of each OT book, in the whole NT and in each NT book:
The above page has another table indicating the number of quotations which differ in meaning from the LXX (in total: 22.5 over 320). This second table is complemented with a table on another page indicating the number of quotations which differ in meaning from the Masoretic text (101.5 over 320):