All the incidents happened on Sunday, 22 November, between 7.30pm and 8.30pm on Old Oak Common Lane.
A man approached three separate women and made sexual remarks before touching them inappropriately.
Officers released a CCTV image of a man they would like to trace as part of their ongoing enquiries.
Anyone who recognises the man in the image or with any information is asked to contact the Metropolitan Police by calling 101 quoting reference CAD6338/22Nov.
Alternatively, tweet @MetCC or contact Crimestoppers anonymously on 0800 555 111.
Police said there have been no arrests and enquiries are ongoing.