Weatherley joins from Smash Hits, part of Emap's performance division, where she was deputy editor and most recently acting editor while a permanent replacement was found for Emma Jones, who is now a Sun columnist.
Weatherley, who replaces Helen Bazuaye, joins as J17 unveils a redesign which has been overseen by Emap Elan consultant editor Ally Oliver and youth group art director Matt Phare.
The first issue of the redesign launched this month includes a Department of Education mini-mag providing careers advice.
Weatherley has previously worked at Sleaze Nation, 19, Company, Bliss and NME.