The well known pensions commentator and speaker will leave Royal London where he has worked as policy director since 2015.
At LCP he will work on the firm’s client service offering to help adapt it for the future “in the context of an ever-evolving regulatory environment”, LCP says.
He will also help LCP spearhead campaigns to help the wider pensions industry stay up to speed with change and member needs.
LCP advises 43 of the FTSE 100 companies and has grown strongly in recent years.
It achieved income over the past year of £114.9 million, an 8.5% increase on the previous financial year.
Sir Steve Webb said: “I have known and worked with several people from LCP over the years and I know that the firm places great emphasis on client care and creating a working environment that enables talent to flourish.
“Their people-centred ethos means that the needs of pension scheme members is always uppermost in the work they do. After four happy and productive years at Royal London working with some great people, I can’t think of a better place for my next move especially as LCP is experiencing an exciting period of growth.”
Aaron Punwani, chief executive of LCP, said: “Steve Webb was not only the UK’s longest serving Pensions Minister, but also the most highly regarded pensions politician the UK has known in recent times.
“He continues to be widely respected throughout our industry and across the political party spectrum. Steve’s insight will help LCP to shape the future of the pensions industry and to adapt our services to meet the future needs of our clients.”