Wa alaykum salam wa rahmatuLlahi wa barakatuHu,

Ibn Hajar mentions that wearing a turban is sunnah in prayer. (Tuhfat al-Muhtaj v. 3, p. 36-37)

Imams Muslim, Abu Dawud, and others related that the Prophet Muhammad entered Makkah while wearing a turban. (Sahih Muslim v. 9, p. 1641; Sunan Abi Dawud v. 3, p. 1748)

There are also hadith that mention that the Prophet Muhammad entered Makkah wearing a helmet. Qadi ‘Iyad reconciled between the two hadith – the one of the Prophet Muhammad wearing a helmet on entering Makkah and the one of him wearing a turban – by explaining that the Prophet Muhammad wore a helmet upon first entering Makkah. Then after conquering it, he took off the helmet and wore a turban. (Sharh Muslim v. 9, p. 1642)

Therefore, wearing a turban is found in the sunnah.

And Allah knows best.

Shafiifiqh.com Fatwa Dept.