Jmabel (active wikipedian: October 28, 2003—present) is a Wikipedian administrator who is often sought out by other Wikipedians for advice and assistance. He is a leading proponent of the theory of Wikipedia's systemic bias and is the founder of WikiProject Ethnic groups. Many of his edits concern Argentina, Catalunya, the French Revolution, Romania, Seattle, Yiddish theater, and African-American topics. He also chimes in on music-related topics, including folk rock, early punk rock, and grunge music.

He has been a leading influence in Forum for Encyclopedic Standards and the movement to counteract systemic bias, and is largely responsible for the current structure of Wikipedia:Pages needing translation into English and Wikipedia:Translation into English. He has translated hundreds of articles or portions of articles from the Spanish, German, Catalan, and Romanian Wikipedias, and occasionally from others.

He and DanKeshet ^[wikibio] wrote the bulk of Wikipedia:Researching with Wikipedia.

Jmabel has one of the most diversified scopes of contribution in the Wikipedia community, which has stretched his resources—causing him to sometimes decline entering new areas of Wikipedia. When Jmabel commits to a project he often brings new perspectives and remains helpful and responsive even when a project may not be his priority. The Coordinator of WikiProject: U.S. regions, JCarriker, considers Jmabel to have played a pivotal and positive role in the formation and evolution of that project, though Jmabel (perhaps modestly) feels he has only played a minor role in it.