Who was he? He was a 14th century priest around Britain and sometimes lecturer in theology at Oxford (it being the 14th century, these roles were not clearly defined). Wycliffe became increasingly critical of the Roman Catholic Church in his day, seeing the majority of it as largely corrupt or, at the very least, needlessly elitist. He believed that the Church should be poor, giving away most of its money, which stands in stark contrast to the rather ornate buildings and relics the Church had begun to amass during this time. He also posited a distinction between the visible Church (which he saw as mostly corrupt) and the invisible Church, which he believed was composed of those who were genuinely redeemed. He is, though, most famous for advocating his belief that the bible should not only be translated in the common language of the people, but that it should be made accessible to them, which would also entail an increase in literacy. His followers were named “lollards” as an attempt to disparage them, suggesting that their speech sounded something like lollard-lollard (like the Ancient Greek suggestion that non-Greeks were Barbarians). Instead, his followers took this as a name of honor. Interestingly, Wycliffe also advocated for a separation of the secular state away from the influence of the Church (and vice versa).
Where might I have heard of him? A number of schools and organizations have taken on the name, perhaps the most well known of which is Wycliffe Bible Translators, who specialize in translating the bible into other languages.
Fun Fact: Wycliffe was not declared a heretic until after his death. At this point, his body was exhumed, burned, and the ashes scattered. That was, of course, not the first time his detractors had attempted to do something similar (but clearly the last time).
Why was he important?Although there seem to have been other bible translations in English (at least of sections of the bible) in circulation, and many nobles had the bible in French, Wycliffe began a concerted effort to get a comprehensive bible in a wide circulation. He used the Latin Vulgate as his base and may have personally done the translation of the Gospels, the entire New Testament being completed at, or very near, his death. He would go on to influence other major advocates of having the bible in the vernacular such as Jan Hus, William Tyndale, and Martin Luther.