His Father John Latsis started building the family fortune in 1938 as a trader and later a ship-owner. He grew his Business into a fleet of ships by the 1960s. He built up a number of Business interests in the areas of shipping, real estate, construction and oil, plus banking and Finance. Latsis joined the family Business initially in the banking arm.

Spiro Latsis is the son of Yiannis Latsis and Erietta Tsoukala. He has two sisters, Marianna and Margarita Latsis. He was educated at the London School of Economics (LSE) where, in 1968, he obtained a bachelor's degree in economics. In 1970, he received a master's degree in logic and scientific method. He went on to pursue his doctorate and obtained a PhD in philosophy from the LSE in 1974.

From 1989, Latsis became a Director of some companies within the EFG Group, the family banking Holding Group, including Private Financial Holdings Limited which became EFG Private Bank Limited in London, and EFG Consolidated Holding SA in Luxembourg. The following year, he also assumed the role of Director of Eurofinanciere d’Investissements SAM in Monaco and became a non-Executive Director of Eurobank Ergasias SA in Athens. Dr Latsis officially assumed the role of Chairman of the EFG Group in 1997.

After the death of his Father in 2003, Latsis took over the direction of the Latsis Group of companies. Since that time, Latsis, while remaining Chairman of EFG Bank (the family bank holding company) has become a Director of EFG International and Consolidated Lamda Holdings, serves as President of Societe d’Etudes et Economiques in Geneva, and is Chairman of several other companies including Paneuropean Oil and Industrial Holdings S.A. in Luxembourg.

The Latsis family fortune, managed by Spiro Latsis, includes more than 42% in Hellenic Petroleum, a major petroleum player in Southern Europe, through its ownership of Paneuropean Oil and Industrial Holdings S.A.. The Latsis group also controls Lamda Development, a real estate group based in Athens. Lamda Development projects include The Mall Athens, which opened in 2005, and Golden Hall Mall, also in Athens. Latsis also started PrivateAir, a jet charter Service with over 50 planes in its repertoire serving affluent European and American travelers, and which he has since sold.

In 2006 Latsis received an honorary doctorate from Witten/Herdecke University in Witten, Germany recognizing his work in the field of economics.

In addition to his various Business holdings, Latsis (with his family) helps to fund the John S. Latsis Public Benefit Foundation and the International Latsis Foundation in Geneva. In 2012, he transferred around $300 million of his Greek banking stock holdings to various members of the Latsis family, with a contribution also going to the Foundation.

In 2015 Latsis was the second wealthiest Greek, ranked #782 on the 2015 Forbes list of the world's richest people. Latsis saw his wealth significantly decline during Greece's recession, with stocks of his EFG Eurobank, Lamda Development and Hellenic Petroleum all falling significantly in 2011, but recovered in 2013. Latsis invited the President of the European Commission, José Manuel Durão Barroso, who had been a student friend at the London School of Economics, to be a guest on his yacht. Subsequently, allegations were made in the press that this somehow influenced Commission decisions but these have been disproved.

The family's largest holding is its EFG Bank European Financial Group in Luxembourg, a private banking group that operates in many jurisdictions. The Group holds over 40% of EFG International listed in Switzerland on the Zurich Stock Exchange, which is a global private banking group offering private banking and asset management services. EFGI's group of private banking businesses operates in around 30 locations worldwide, with 3,572 employees and manages CHF144.5bn of client assets as at 31 December 2016.