Small groups attacked shops and banks with a stand-off in Piccadilly. There have been 214 arrests and 66 people injured, including 13 police.
Ministers say the cuts are necessary to get the public finances in order.
There have been separate incidents involving a number of protesters, some with their faces covered by scarves, away from the main march:
* A sit-in organised by the campaign group UK Uncut took place at Fortnum & Mason department store in Piccadilly. The group has previously mounted protests against tax avoidance measures by big businesses.
* A bonfire was lit by protesters at Oxford Circus, where earlier police said light bulbs containing ammonia were thrown at officers.
* Topshop on Oxford Street had its windows smashed and was doused with paint.
* Missiles were thrown at the Ritz Hotel, Piccadilly
* Bank branches including the Royal Bank of Scotland were attacked with paint and had windows broken, while branches of HSBC and Santander were broken into.
Scotland Yard said there had been 202 arrests for public order offences, criminal damage, aggravated trespass and violent disorder.