Tory MP Fiona Bruce asked whether she welcomed her acquittal by Pakistan's Supreme Court.
May responded in the Commons by instead saying: "The news out of Pakistan will be very welcome to her family and to all of those who have campaigned for her release."
Christian mother Asia Bibi was released after spending eight years on death row after being accused of blasphemy.
After numerous delays, judges finally ruled there was insufficient evidence for her conviction.
Theresa May did however speak out against Pakistan's use of the death penalty.
She said: "Our longstanding position on the death penalty is well known. We call for its abolition globally."
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