McNicholas, 28, who was editor of IPC's dance music magazine Muzik is the same age as outgoing NME editor Knowles.
McNicholas is a former MixMag and Ministry journalist, although he says he has been a long-time reader of the NME. His experience appears to lie in writing about dance music, rather than the NME's staple diet of pop and indie music news.
McNicholas said: "I've been reading [the NME] since I was 15 and it's something I've always dreamed of doing. Actually being appointed to the position is mind-blowing. I'll be taking over in the paper's 50th anniversary year, which is an additional honour."
He takes over in the same year that NME lost its lead as the number one weekly in the music market to Kerrang!.
In the last set of ABCs, NME recorded an ABC of 70,456, a slight increase on the previous period, but trailing Kerrang!'s 76,841.
He will no doubt be expected to reduce Kerrang!'s lead over the NME, if not reverse it.
In the nine months since he was made editor of Muzik, McNicholas relaunched the magazine with a new format and logo. He also repositioned the magazine, which trails Emap's more mainstream dance music magazine MixMag by around 60,000 readers, to appeal to more serious dance music fans.
His intentions for NME, however, are as yet unclear. It is unlikely that he would be expected to overhaul NME, which was recently revamped with a new size to celebrate its 50th birthday and to allow it to sit on newsstands next door to its rivals.
However, McNicholas has said he wants the paper to be "the most exciting, witty, opinionated and informative music magazine in the world".
NME editorial director Steve Sutherland will continue to oversee the NME's editorial output until McNicholas takes up his new position in August. IPC Media said an announcement about a new Muzik editor will be made shortly.
Explaining about the swift announcement about McNicholas's appointment, Sutherland said: "Having known for some time that Ben had to leave NME, I had the opportunity to meet with and consider the talents of many of the leading figures in British music journalism and was delighted to discover that the prime candidate for the role was already working for IPC Ignite."
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