The building is topped by a four-faced clock, visible from 25 kilometres (16 miles) away. The clock is the highest in the world at over 400 metres (1,300 ft) above the ground. It replaces the Allen-Bradley Clock Tower in Milwaukee, Wisconsin as the tallest clock tower in the world. The clock's face is also bigger than the previous record holder as the largest clock face in the world, the Cevahir Mall clock in Istanbul.

Each of the clock's four faces measure 46 m (151 ft) in diameter and are illuminated by 2 million LED lights, with four oriented edges, just above the clock alongside huge Arabic script reading: “God is the Greatest” on the north and south faces and on the west and east theKoran. Four golden domes on pillars on all the corners are also present. Another 21,000 white and green coloured lights, the same as the Saudi Flag, fitted at the top of the clock, will flash to signal Islam's five-times daily prayers, and will be visible as far as 30 km (19 mi) away. On special occasions such as new year, 16 bands of vertical lights will shoot some 10 kilometres (6.2 miles) up into the sky. The clock's four faces will be covered with 98 million pieces of glass mosaics. The Saudi coat of arms is displayed at the centre of each clock behind the dials. The minute hand is 22 m (72 ft) long, while the hour hand is 17 m (56 ft) long.