Is Quora an acceptable source on Wikipedia?

Quora answers are https://en.wikipedia.org/wiki/Wikipedia:Verifiability#Self-published_sources. As the linked section of Wikipedia's verifiability policy explains, these are generally to be avoided as unreliable. However, an expert's testimony might be acceptable as reliable, provided it's not making particularly extraordinary claims. That special case is rarely applicable in practice, since when the claims aren't extraordinary, there are almost always better sources to cite on the subject. That's for information in general… As the following section, "https://en.wikipedia.org/wiki/Wikipedia:Verifiability#Self-published_or_questionable_sources_as_sources_on_themselves", explains: Self-published and questionable sources may be used as sources of information about themselves, usually in articles about themselves or their activities, without the self-published source requirement that they be published experts in the field, so long as: the material is neither unduly self-serving nor an exceptional claim; it does not involve claims about third parties; it does not involve claims about events not directly related to the source; there is no reasonable doubt as to its authenticity; the article is not based primarily on such sources. TL;DR: Yes, in theory you can cite Quora, but Quora answers count as self-published sources, which should be used sparingly and carefully.

Generally, no. Wikipedia requires reliable source. As stated at http://en.wikipedia.org/wiki/Wikipedia:USERG, For that reason self-published media—whether books, newsletters, personal websites, open wikis, blogs, personal pages on social networking sites, Internet forum postings, or tweets—are largely not acceptable. This includes any website whose content is largely user-generated, including the Internet Movie Database, http://Cracked.com, http://CBDB.com, and so forth, with the exception of material on such sites that is labeled as originating from credentialed members of the sites' editorial staff, rather than users. For example, Wikipedia itself is not regarded as a reliable source. Since anybody can post anything on Quora, I personally do not think that it is a reliable source. However, it really depends. Say, the CEO of Quora answered a question about Quora itself, we may or may not take that as a reliable source for the article Quora on wikipedia.

"Nothing on Quora is systematically fact-checked, so it's not an acceptable source for factual information on Wikipedia." "Wikipedia requires reliable source." "Quora answers are not usable as sources." Reliable means: consistently good in quality or performance; honest, responsible, established, proven Quora requires and strictly and effectively enforces users to be verifiably real people- publishing their own content- under their own name. Quora has extremely high standards of quality, and high performance is consistently achieved through actively promoting, encouraging, defending, and rewarding high achievement. It goes without saying that Quora is honest about mistakes and failures, responsible about ethics and moderation, established as an extraordinarily helpful source of information and advice of all sorts and for all kinds of people, and proven to attract and maintain the active participation of countless highly esteemed and credentialed professionals and scholars, and specialists from all fields and disciplines, and from institutions all over the world. And as for fact-checking, everything on Quora is systematically fact-checked, as a multitude of experts read the answers and will report factual inaccuracies so that the answer can be suspended and the errors corrected.