Dainton left Credit Suisse earlier this year, having previously run Credit Suisse's equities business in Europe and later co-headed the Swiss bank's markets business in the region.
In his new role at Barclays, he will be based in London, and report directly to Tim Throsby, the head of Barclays' corporate and investment bank. Throsby, who joined Barclays in January this year, was previously global head of equities at JPMorgan.
"Stephen will work with the Equities leadership team to accelerate delivery of our strategy to grow revenue and market share with a strong focus on our clients, conduct and controls," Throsby said in a memo announcing the appointment. A spokesman for Barclays confirmed the contents of the memo.
Barclays generated £455 million in equities revenues in the first half of the year, up 12% from a year earlier, with the bank citing growth in equity financing and cash equities revenues. The unit generated 17% of Barclays' corporate and investment bank revenues in the period.
On an earnings call in late July, Jes Staley, Barclays CEO, highlighted the importance of technology in the equities business.
"There are clearly parts of the institutional market where technology is extremely important and it is defining the economic characteristics," he said. "I think the most salient would probably be the cash equities business, in which data processing and algorithms are critical, both for the cost of that business, as well as the revenues."
Dainton's appointment follows a series of moves in Barclays' equities business. Mike Di Iorio, who had been global head of equity sales at Barclays, moved to Credit Suisse earlier this year, while Pascal Bandelier, who had been head of US equities execution, moved to Cantor Fitzgerald.