The UK's sharing economy sector, which include peer-to-peer lending platforms and crowdfunding sites like Kickstarter, car sharing apps such as Uber, car rental firms and music streaming services like Spotify, is currently worth around £7bn.
The audit firm said this industry could see a 20-fold increase in growth by 2025.
Across Europe, sharing economy transactions could rise to €570bn (£476bn) by 2025, up from its current value of €28bn.
Economists at the firm said that, despite the UK's decision last Thursday to divorce from the EU, the sharing economy's rapid expansion should still be on track.
Rob Vaughan, economist at PwC, said: "While our analysis was carried out ahead of the UK’s vote to leave the EU, at present we do not expect the decision to alter our long-term trajectory for the sharing economy's substantial growth.
Read more: 2.5m people a month are now part of the sharing economy
"Economic and political uncertainty will act as a headwind to growth across every sector of the economy in the short-term, but the fundamental drivers of the sharing economy – technological advancements, demographic change and urbanisation – will continue to drive adoption in this space over the long-term."