The 32-year-old forward previously impressed in the Premier League for Norwich City under the guidance of current Villa boss Paul Lambert.
Holt joined Wigan from Norwich in the close season, but has found games and goals hard to come by for the Championship outfit, scoring just twice in nine league starts and seven substitute appearances.
Lambert is delighted to have boosted his forward line, with Libor Kozak having been ruled out for the remainder of the season earlier this month after breaking his leg in training.
"Losing Libor was a blow to us, obviously," Lambert told Villa's official website.
"When I knew Grant had become available it was something I wanted to pursue quickly because he'll add strength and experience to what is still a young squad overall.
"Having worked with him for three years at Norwich, I know what he can do and that's important.
"Coming back into the Premier League will rekindle that desire in him to succeed again at this level and, if he can replicate what he did in those three years at Norwich over these next few months here at Villa, then he'll make an impact, that's for sure.
"We're looking at one or two other positions as well but this is good business for us and he'll be a really strong influence."
After helping Norwich rise from League One to the Premier League, Holt contributed 15 goals in the Norfolk club's first season back in the top flight in 2011-12.
However, he managed just eight the following season and has endured a frustrating time since joining Wigan in July for a fee reported to be around £2million.
"It's a massive opportunity for me personally, an opportunity I couldn't turn down,” said Holt regarding his switch to Villa Park.
"To be able to come back into the Premier League, especially at a club as big as Villa, is fantastic and it's an opportunity for me to work with the gaffer and his staff again as well.
"He's able to get the best out of people, there's no doubt about that."
