Can I wear perfume while fasting?

The doubt nearly always comes from mixing two states that have different rules.

Fasting: what is avoided is eating, drinking and intimacy during daylight hours. Perfume is not on that list.

Ihrām (the pilgrim's state in Hajj or ‘Umra): there perfume *is* avoided, along with cutting hair and nails, hunting, and other things. A different state, and a different list.

So during Ramadan you may wear perfume, use cream, deodorant and hair oil as normal.

The one qualification some scholars mention is incense or bukhūr whose smoke is deliberately and lengthily drawn in, since it is a substance with body that can reach the throat. Perfuming the skin or clothes raises no such question.

The general framework: “It has been made permissible for you the night preceding fasting to go to your wives for sexual relations. They are a clothing for you and you are a clothing for them. Allah knows that you used to deceive yourselves, so He accepted your repentance and forgave you. So now, have relations with them and seek that which Allah has decreed for you i.e., offspring. And eat and drink until the white thread of dawn becomes distinct to you from the black thread of night. Then complete the fast until the night i.e., sunset. And do not have relations with them as long as you are staying for worship in the mosques. These are the limits set by Allah, so do not approach them. Thus does Allah make clear His verses i.e., ordinances to the people that they may become righteous.” (Qur’an 2:187)

And a practical observation: presenting yourself clean and smelling good is something the tradition values, and Ramadan is no exception. The month does not ask you to neglect how you look or smell; it asks you to hold back your appetite and your tongue.