What is the ruling on a woman wearing a ring on the index or middle finger?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

The prohibition of wearing a ring on the index or middle finger as reported in the hadeeth is specific to men. Imaam Ahmad ibn Hanbal stated this in accordance with the opinion of the three Imaams (Abu Haneefah, Maalik and Ash-Shaafi‘i) as As-Saffaareeni stated in his book Ghithaa’ Al-Albaab Fi Sharh Manthoomat Al-Aadaab.

Imaam An-Nawawi said:

The Muslims have unanimously agreed that it is from the Sunnah for a man to wear the ring on his pinky finger. It is disliked for a man to wear the ring on his middle finger and the one next to it (i.e. the index finger). However, this undesirability does not reach the degree of prohibition.

Therefore, it is not disliked for a woman to wear a ring on whichever finger she likes.

Allaah Knows best.