The 27-year-old left-back has been with Rovers for two seasons after making a £1.5 million move from Liverpool.
Since Warnock has been at Rovers he managed to earn a full England cap when he played in a friendly game against Trinidad and Tobago some 15 months back.
"Villa can confirm they are in discussions with Blackburn Rovers over the transfer of Stephen Warnock," read a brief club statement.