Is it necessary to perform ablution again after ghusl?

Since ghusl also includes ablution, there is no need to perform ablution again unless something occurs that invalidates it. Indeed, ʿĀʾisha reported that the Messenger of Allah (peace be upon him) did not perform a separate ablution for prayer after performing ghusl. (Abū Dāwūd, Ṭahārah, 96 [250]; Tirmidhī, Ṭahārah, 79 [107]) ʿAbdullāh ibn ʿUmar also narrated that the Prophet (peace be upon him) said, “What ablution is more comprehensive than ghusl!” (Ṭabarānī, al-Muʿjam al-Kabīr, 12/371 [13377]), thus indicating that there is no need to perform ablution again after ghusl.

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