On which hand and finger should a ring be worn

The ring can be worn on either the right hand or left hand as both are established from Hadith. Rasulullah Sallallahu Alayhi Wa Sallam wore his ring on the little finger. It is also permissible to wear it on the ring finger.

It is disliked for a man to wear a ring on the middle and index finger.

Sayyiduna Ali Radhiyallahu Anhu relates that Rasulullah Sallallahu Alayhi Wa Sallam forbade me from wearing a ring on this finger and this finger. The narrator says he pointed to the middle and index finger. (Sahih Muslim)

Imam Nawawi and ‘Allama Tibi have classified wearing a ring on the middle and index finger to be Makruh Tanzihi (a light form of reprehensibility) and not Haraam.

Rasulullah Sallallahu Alayhi Wa Sallam would wear his ring on the little finger as it is used less frequently than the other fingers and has less chance of being a hindrance when using one’s hand. (Takmila Fath al-Mulhim 4:121)

The above applies to men specifically. It is permissible for women to wear rings on all fingers.

And Allah Ta’ala Knows Best