1101_hugh_singleHugh Grant is a daddy for the first time -- but there's a mystery surrounding who the baby mama is!

toofab has confirmed that Grant welcomed a baby girl, but the mother's identity remains a secret.

“He and the mother had a fleeting affair and while this was not planned, Hugh could not be happier or more supportive," a rep tells toofab.

"He and the mother have discussed everything and are on very friendly terms.”

Grant was last linked to Chinese actress Tinglan Hong back in April.

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