The FA said in a statement: "It is alleged the Chelsea manager's behaviour in re-entering the field of play in or around the 90th minute of the fixture and approaching the match referee amounted to improper conduct."
Mourinho has until 6pm on March 24 to respond to the charge.
The FA rule book says managers must not leave the confines of their technical area during the match
After the game, Mourinho pointed out several people had gone on to the pitch.
The Chelsea manager said: "I was two-three metres inside the pitch or four-five metres, but there was like 10 persons there
It was me, my two assistants, (Villa boss) Paul Lambert, Paul's assistants..
"And there was [Gabriel] Agbonlahor, who come in and made an aggression on Ramires from behind.
"So if I was sent off because I was on the pitch, I ask why not the others, especially one player that made an aggression on another one, Agbonlahor on Ramires?"
He was sent to the stands after Ramires' red card for a studs-up challenge on Karim El Ahmadi.
Mourinho also confirmed he had tried to speak to Foy after the game.
He said on Monday: "I tried to speak to Mr Foy twice
I tried to speak on the pitch and I tried in the dressing rooms
"In the dressing rooms I tried to ask politely, can you give me five seconds? And he refused."
Mourinho's sending-off was his second of the season - he was fined ?8,000 by the FA following his touchline dismissal against Cardiff in October.
Source : PA
Source: PA