Yes. Your employer needs to provide at least one toilet for your workplace, and separate toilets for men and women if workers are of both sexes in your workplace.
The number of toilets provided is governed by this formula (calculated separately for men and women):
1-5 workers = 1 toilet
6-25 workers = 2 toilets
26-50 workers = 3 toilets
51-75 workers = 4 toilets
76-100 workers = 5 toilets
If different toilets are only to be used by different group of workers in your workplace (eg: office workers and factory workers), the calculation needs to be done separately for each group.
If the toilets where you work are also used by members of the public, the number provided needs to be increased so that staff can use them without delay.