Is the Friday prayer valid for someone who misses the sermon (khutbah)?

The sermon (khutbah) is one of the conditions for the validity of the Friday prayer. A Friday prayer performed without the sermon is not valid. Therefore, at least one man must be present while the sermon is delivered. However, it is not a requirement to catch or listen to the sermon in order to perform the Friday prayer. Accordingly, the Friday prayer of someone who, due to an excuse, cannot catch or hear the sermon is valid. If a person cannot make it in time to listen to the sermon and even joins the second rak‘ah of the Friday prayer, after the imam gives the salām, he stands up and completes the prayer by performing one more rak‘ah. (Ibn al-Humam, Fath al-Qadir, 2/65-66)

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