McManus (pictured) joined Nutmeg in February 2015 following three years at Coutts as associate director.
Prior to Coutts, he held roles at CreditSights as an associate and Citi Family Office as an investment analyst.
The announcement follows Nutmeg’s chief investment officer, Shaun Port, stepping down after seven years with the company.
McManus’s appointment is one of three promotions to director-level roles the investment platform has made. Pacome Breton and Brad Holland have been promoted to director of investment risk and director of investment strategy, respectively.
Their duties involve leading their respective areas that construct Nutmeg's investment team, including strategy and macro allocation, ETF selection and allocation, and investment risk and quant research.
The promotions support Nutmeg’s bid of ensuring the company’s success is an inclusive effort as its philosophy is built around a team approach rather than an individual star manager.
Martin Stead, chief executive officer at Nutmeg, said: “We have recruited the best and brightest minds from the worlds of investment management, exchange-traded funds and trading, to build industry-leading wealth management and trading teams.
“Together, these teams have introduced fractional ETF share capability to UK retail investors, they have led the market in socially responsible investing, and they have exported their expertise to new markets in Asia.”