There is a temporary musollah available during the Ramdhan period at the Geylang Bazaar. It is located near to stalls B86-B87 (for muslimin) and B87-B88 (for muslimah). Wudhu amenities available within the musollah and it is air-conditioned. Prayer mats and telekung are provided. 

Alternatively, after the bazaar has ended, you can go to the musollah at Wisma Geylang Serai which is just behind this temporary musollah.

​From CGH A&E drop off point,

1. Walk past the pharmacy and 1983 and down the walkway till you reach the ATMs (opposite 7 Eleven)
2. Turn left towards Umisushi and then turn right to where Mr Beans is (just outside of the Kopitiam). There is a door just past Mr Bean and just before Kopitiam (on the left), leading to Staircase 9. Go past the door leading to Staircase 9. There is another door before you will reach the musollah.
3. The Musollah is under the staircase and it is shared for both Muslimah and muslimin. 1 prayer mat provided, no telekong. Wudhu can be taken at the toilets just before Mr Bean

From the Integrated Building Drop off point,

1. Walk past the pond/water feature (towards Mr Bean). When facing Mr Bean, there is a door on the left leading to Staircase 9 (just beside the Kopitam).
2. Go past the door leading to Staircase 9. There is another door before you will reach the musollah.
3. The Musollah is under the staircase and it is shared for both Muslimah and Muslimin. 1 prayer mat provided, no telekong. Wudhu can be taken at the toilets just before Mr Bean.

There is a musollah at Shaw House [Lido]  350 Orchard Road, S [238868] at level 10.  Directions :

From Orchard MRT...
1. Take Exit E to Wheelock Place and follow the signs to the Ion Patterson Link which will lead you to the Basement of Wheelock place. (UPDATE 22/04/2022: The escalator leading to Tangs level B1 is closed so you have to go by the Level 1 of Tang instead.)
2. Once there, turn right to the underground connector to Shaw House and walk straight and go up the series of escalators to the ground/street level of Shaw House where you see the Isetan entrance (between the 2 escalators).

From the main entrance of Shaw House...
3. Cut across Isetan (ground level) and turn right till you see the Shaw Centre sign (between SKII and FANCL, you will see Nike in the background). 
4. Walk towards Nike and then turn left till you see Lift Lobby A [near to Nike store and right beside the ATMs]. Please do not take Lobby B on the right.
5. Take the lift at lift Lobby A to Level 10.
6. Turn left to Staircase B after exiting the lift lobby. The musollah is located in the staircase area. It is a shared musollah for muslimah and muslimin. Prayer mat provided. Please bring your own telekung.
Ablution can be performed at  the toilet on the right after exiting the lift lobby A on level 10. There are 2 pairs of slippers/sandals for use. 
Telekung is donated by Sister Azlina.

A much easier and faster way would be if you come from the drop off point at Shaw Centre. The Lift Lobby A is located on the right, just behind the security counter. Then just follow step 5 onwards.

​Credits to Brother Shah

Do note that this is an unofficial musollah that is unbeknownst to the building's management. Hence, praying materials are not provided. 

How to get there:
Musollah is located at level 4 just near the main lift lobby. Take main lift near Macdonald's to level 4. Upon exiting lift, enter the door on the left then make a right turn. Walk down the aisle towards the carpark exit door, you'll see a wheelchair assistance bay, that's where the musollah is located at. Ablution can be done at nearby toilet/nursing room. The praying area can take up to 3-5 people. Please bring your own sejadah and telekung.

Alternatively, nearest musollah is at Assyafaah Mosque.

Credits to a fellow Sister