The actor pointed out even her husband, Anand Ahuja, changed his name after tying the knot but nobody spoke about that.
The move did not go down well with many people who expressed their disappointment that a feminist icon like her resorted to patriarchy.
In a video interview from Cannes, where Sonam walked the red carpet for cosmetic brand L'Oreal Paris, the actor said she has always been a feminist and the choice to change her name rests with her and no one else.
"Kapoor is also my father's name, so it's a man's name anyway. I chose to keep both. Anand has also changed his name but nobody wrote about that. I just decided to do it on social media because that's my platform, to say that I've made a choice.
"It's my personal choice, nobody put a gun to my head... You should ask him (Anand), he has also changed his name and decided to add something as well," she says.
Anand has also updated his name on Instagram, adding an 'S' before Ahuja.
The "Neerja" actor says neither her husband nor his family had asked her to change her name and neither did she ask her husband to do it.
"The whole idea of feminism is to have equal opportunities and the choice to do what you want to do. So whether I want to or don't want to change my name is my personal choice," she says.
Sonam says sticking to the surname of the family is also patriarchy as it is a man's name.
"If you can give respect to your father, you can give that same respect to your husband. It's a cyclical thing which needs to break somewhere... I want to be a part of Anand's family and he is a part of my family as well," she says.
The actor says it is a complicated discussion but this is her choice.
"Somebody judging me for my choice is not what feminism stands for," she adds.
"(I have been) half there, half here. Since two years I've been going there, nobody noticed. I go there for four-five months and then I'm back to Mumbai. My life won't change. What has been happening since the last two-three years will remain," she says.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)