The number of mosques in Dubai was 1,418 in 2012 according to Gulfnews article.
Though all mosques in Dubai are managed by the Islamic Affairs and Charitable Activities Department (IACAD), mosques can be built by individuals, clubs, associations, companies, etc. As many as 495 or 34 per cent of the mosques in Dubai were built by IACAD, while 478 mosques were built by philanthropists followed by different government departments that contributed towards the building of 283 mosques.
633 mosques are located in Deira (most of Dubai’s mosques), while 438 are located in Bur Dubai. Around 36 per cent of these mosques have Friday prayer service. The emirate of Dubai has mosques of various sizes from those accommodating 100 worshippers to those that can accommodate more than a thousand. Around 168 of the total number of mosques in Dubai can accommodate more than 1,000 worshippers at a time, while there are around 500 mosques that can accommodate 100 people. The mosques in Dubai together can accommodate around 600,000 worshippers.
The 3 main mosques in Dubai

Jumeirah Mosque
The Jumeirah Mosque has become renowned because it is the only mosque in Dubai which is open to 6 days a week (no on Fridays). It is preferred to dress modestly, however traditional attire can be borrowed from the Mosque.
Timings
Tuesday & Thurday
From 10 AM
Price
AED10
Transport
Metro Station
(Red line)
Then take a cab

Ali bin Abi Talib Mosque
Ali bin Abi Talib Mosque is a simple one, in the textile area of Bur Dubai Souq, yet notable for its domes and gently tapering minaret. The mosque is beautifully lit a night and can be seen from Baniyas Road in Deira, on the opposite side of the Creek.
Timings
Location
Transport
(Green line)

Dubai Grand Mosque
Dubai Grand Mosque is located opposite Dubai Museum. The mosque was built in 1998 and is a replica of the original one from 1900. The mosque has Dubai’s tallest minaret (70m high) and more than 50 small and large domes.
Timings
Location
Transport
(Green line)