This latest transaction adds £320m in assets under advice or management to Kingswood and boosts its total AUA to £5bn.
It also increases Kingswood's client-facing adviser numbers to 67 and they look after over 16,000 active clients.
Kingswood says three further acquisitions are also in the pipeline.
Regency, which is based in Egham, provides independent financial advice to individuals and corporates mainly in Greater London and employs 12 people, including 6 IFAs advising a total of 1,000 clients.
The takeover deal, subject to regulatory approval, is worth £3.45m in cash paid over a 3-year period, says Kingswood which has expanded rapidly in the UK and overseas in recent years.
Some £1.38m will be paid at closing and the balance paid on a deferred basis subject to Regency hitting recurring revenue and EBITDA targets over 3-years.
An additional deferred payment of a maximum of £1.2m is potentially payable at the end of the 3-year period subject to achievement of an excess EBITDA target over the deferred period.
Regency was founded by the current principal's grandfather in 1965. Kingswood says principal Dominique Vinecombe has continued her grandfather's legacy and, supported by Alan Lander, has grown the business across Greater London mainly through organic growth.
Regency is focused on recurring revenue and in the 12 months to 31 January it produced EBITDA of £0.55m. As of 31 January 2020 it had total assets of £2.6m and net assets of £2.1m.
Kingswood will fund the deal by issuing new convertible preference shares in a deal with HSQ Investment, a firm run by private equity business Pollen Street Capital Limited.
Gary Wilder, group chief executive at Kingswood, said: "We look forward to welcoming Dominique Vinecombe and the Regency team to Kingswood.
“Dominique's grandfather founded the business 55 years ago, and we are honoured she has entrusted us to carry on the legacy of outstanding customer service for which the business is renowned.
“Dominique will continue with the business and we look forward to working with her to grow and expand the services offered to clients. There is a major opportunity over time to migrate existing and new clients to Kingwood's extensive and growing range of managed investment solutions on our DFM platform, underpinning the value of a fully integrated wealth and investment management business.”
Kingswood has bought a number of UK adviser firms in recent year and also expanded overseas. Earlier this year it acquired US wealth manager Chalice and signed terms to acquire a majority stake in a second US adviser, Manhattan Harbor Capital.
Kingswood has offices around the UK including Derby, London and Sheffield and overseas in Johannesburg, South Africa and New York.