The 40-year-old took charge in 2021 following spells as manager of Sheffield United and cross-city rivals Birmingham.
Ward led Villa to ninth in 2021-22 and then a best-ever WSL finish of fifth last term, with the club currently seventh with two games to go of what is going to be her final campaign in charge.
"To step down from my post here at Aston Villa has been the hardest decision of my managerial career, but I know it is the right one for my family and I," she said.
"Managing a great club like Aston Villa has been a full-throttle job and I have always given the role 100 per cent dedication.
"However, I now believe it is the right time for me to prioritise the other important things - such as my daughter and the rest of my family life.
"I am immensely grateful to (president of football operations) Monchi and (director of football operations) Damian Vidagany who tried so hard to encourage me to stay in the role, but I know it is the right time to step down after our last game of the season."
Villa said in a statement that Ward "has established the club as a force in the top-flight of women's football" and went on to highlight her achievements in charge.
The WSL club said "an update on the manager's position will made in due course", with the home game against Manchester City on May 18 to be her final match in the hotseat.
Monchi, Villa's president of football operations, said: "Carla came to us a few weeks ago and spoke of her plan to step down.
"We have had extensive dialogue with her to see if there was anything we could do to persuade her to stay, but she is adamant that she wants to take a break from the game.
"Therefore, on behalf of everybody at Aston Villa, I want to place on record our grateful thanks to Carla for everything she has achieved with us and wish her well for the future."