A man who allegedly spat on a strangers baby because he thought 'he didn't like him' has been denied bail.

Derek Frederick Brimson was charged with common assault at Parramatta Bail Court on Saturday for the alleged attack on the boy.

The 67-year-old from Wooloomooloo in Sydney's affluent eastern suburbs allegedly spat on the baby who was in his pram at the time.

Mr Brimson is believed to have approached the 18-month-old, who was in the company of his parents at Town Hall on August 7.

Magistrate Darryl Pearce refused the Mr Brimson's release application and adjourned his matter - involving an 'innocent child'.

He will appear at Central Local Court on August 15.