The 29-year-old confronted referee Jon Moss after being sent off in Sunday's 2-2 draw with West Ham.
By admitting the charge, Vardy, who has requested a personal hearing, could be given an additional suspension to his current one-match ban.
Premier League leaders Leicester have also accepted a charge of failing to control their players.
Vardy will miss their game against Swansea on Sunday but could also sit out the trip to Manchester United on 1 May.
The Premier League's second top-scorer - with 22 goals this season - was shown a second yellow card early in the second half after going to ground in the West Ham penalty area.
He confronted Moss, who was criticised for his performance by Match of the Day pundit Alan Shearer, before leaving the field.
Leicester, who are five points clear of Tottenham, need eight points from their final four matches to guarantee the title.
Their final four matches are against Swansea (home), Manchester United (away), Everton (home) and Chelsea (away).