Questioner: Is it known when the Al-Aqsa Mosque was built?
Shaykh: Yes, indeed. The one who built it is Sulaiman (Solomon), peace be upon him. Could it be [otherwise]?! This is explicitly stated in Sahih al-Bukhari.
Questioner: Yes, indeed.
Shaykh: Yes, indeed.
Source: هل يعرف من بنى المسجد الأقصى ؟