Is it necessary for men to cover their heads during prayer?

The Prophet Muhammad (peace be upon him) and his noble companions, both before and after the advent of Islam, used to cover their heads in daily life due to customary practices and climate conditions. The Messenger of Allah (peace be upon him) performed his prayers in his everyday attire and did not wear any additional or special garments specifically for worship. Sometimes he wrapped a turban over a cap, and at other times he wore a cap without a turban or a turban without a cap. (See: Abû Dâwûd, Libâs, 24 [4078]; Tirmidhî, Libâs, 12, 42 [1736, 1784]; Ibn al-Qayyim, Zâd al-Ma‘âd, 1/130; Muttakî, Kanz al-‘Ummâl, 7/121 [18284-18286])

Some scholars, taking into account these practices of the Prophet (peace be upon him), have considered it sunnah for men to cover their heads during prayer. According to this view, praying with an uncovered head is regarded as leaving a sunnah and is thus considered mildly disliked (tanzîhan makrûh). (Ibn ‘Âbidîn, Radd al-Muhtâr, 1/640; Shurunbulâlî, Marâqî al-Falâh, 131) Other scholars, however, have regarded this as a matter of custom and stated that there is no harm in praying with an uncovered head. (See: Shâtibî, al-Muwâfaqât, 2/489)

In conclusion, it is preferable (awla) to cover the head with a cap, turban, etc., while performing prayer. However, it is also permissible to pray with the head uncovered.

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu