Police were called to an address in Pildacre Lane in Chickenley, near Dewsbury, just before 6am on Monday to a report of an unwell child.
The baby was rushed to hospital, but she was pronounced dead shortly after.
A 26-year-old man and a 24-year-old woman were arrested on suspicion of neglect over the child’s death.
The man remains in police custody, while the woman has been released pending further investigation.
West Yorkshire Police said in a statement: “Emergency services attended the address and the child, a baby girl, was taken to hospital, where she was pronounced deceased a short time later.
“A 26-year-old man and a 24-year-old woman have been arrested on suspicion of neglect in connection with the child’s death and inquiries are continuing.
“The 24-year-old woman has been released pending further investigation, the man remains in police custody.”