In 1976 – 1986, after graduating from the Moscow Aviation Institute (MAI) Viatcheslav Kantor worked as a scientist and headed one of MAI research laboratories.

In 1989-1993 Kantor was Director General of the joint venture Intelmas (intellectual materials and systems). Under his leadership, one of the first computer networks was introduced and installed in Russia, including at branches of the Academy of Sciences.

In 1996-2000 he was an economic adviser to the Chairman of the Federation Council of the RF Federal Assembly.

In 1997, Viatcheslav Kantor was named Honorary Citizen of Veliky Novgorod for his major contribution to development and strengthening of economy, science and cultural heritage of the old city of Novgorod, and improvement of social and living conditions for its residents.

Kantor received the following government awards: Order of Friendship (Russia, 1998), Officer's Cross of the Order of Merit (Poland, 2005), Order of Prince Yaroslav the Wise (Ukraine, 2006), Order of Leopold (Belgium, 2009), Chevalier of the National Order of the Legion of Honour (France, 2012), the Knight Grand Cross of the Order of Merit of the Italian Republic (Italy, 2013), Grand Cross with honours of the State Order for Merit (Romania, 2014), Officer of the National Order of the Legion of Honour (France, 2014, presented in 2015) and The Order of Honour (Russia, 2016).

Since 2000 Kantor has served as President of the National Institute of Corporate Reform (NICR), a non-profit organization uniting top political Leaders, Business Leaders and scholars. The NICR focuses on improving the investment climate in Russia and enhancing the global image of Russian companies.

Kantor serves as the President of the Museum of Avant-Garde Mastery (MAGMA), founded in 2001 in Moscow on Kantor’s initiative. The Museum contains the world’s largest and most important private collection of 20th Century Russian avant-garde art. The Russian art movement flourished from approximately 1890 to 1930 and included such artists as Valentin Serov, Marc Chagall, Chaim Soutine and Léon Bakst.

In addition, he received an honorary doctorate from Tel-Aviv University (2004); the Medal of Merit for Medal “Deserved for Tolerance” by the Ecumenical Foundation Tolerance (2011); and the European Jewish Leadership Award (2012).

As Chair of the World Holocaust Forum Foundation Kantor initiated and organized the commemoration events in Krakow, on January 27, 2005, to mark 60 years since the liberation of Auschwitz-Birkenau. The “Let My People Live!” World Forum was attended by more than 40 heads of states and official delegations, including President of the Russian Federation Vladimir Putin, Vice President of the United States of America Richard Cheney, President of the Republic of Poland Aleksander Kwaśniewski and other distinguished guests.

On September 27, 2006, the Second “Let My People Live!” World Forum to commemorate 65 years since the Babi Yar tragedy was held in Kiev. It was attended by over 60 official delegations.

In 2007, Kantor founded and was elected President of the International Luxembourg Forum on Preventing Nuclear Catastrophe, an international non-governmental organisation uniting leading world-renowned experts on nuclear non-proliferation,materials and delivery vehicles. The Forum was established pursuant to a decision of the International Conference held in Luxembourg on May 24–25, 2007. The conference was attended by over 50 renowned experts from 14 countries, including Sergey Kirienko, Director General of the Rosatom State Atomic Energy Corporation, Mohamed ElBaradei, Director General of the International Atomic Energy Agency (IAEA), Nikolay Laverov, Academician and Vice President of the Russian Academy of Sciences (RAS), william Perry, former Secretary of the U.S. Department of Defense, and Hans Blix, Chairman of the Weapons of Mass Destruction Commission and former Director General of the International Atomic Energy Agency.

Kantor is actively engaged in promoting interfaith dialogue, tolerance and reconciliation in Europe. In 2008, he established the European Council on Tolerance and Reconciliation (ECTR), which he co-chaired with the President of Poland Aleksander Kwaśniewski. Today Kantor serves as the President of the ECTR, while ex-Prime Minister of Great Britain Tony Blair is the Chairman. The ECTR is a non-governmental organization composed of former heads of European states, Nobel Peace Prize laureates and other world-renowned individuals for their achievements in "promoting tolerance". The ECTR was established to fight xenophobia, extremism and anti-Semitism, develop practical initiatives for tolerance, and make recommendations for promoting mutual understanding between peoples. In 2018 the ECTR has announced the establishment of the Kantor Prize for Secure Tolerance. The Prize will amount to one million Euro and will be awarded bi-annually. The first recipient is to be selected in 2020. Kantor Prize for Secure Tolerance will be awarded for original thinking and research on how the theory and practice of tolerance should be re-imagined to meet the new challenges of a globalized world and the highly diverse and sometimes fragmented societies it contains.

The Third World Forum “Let My People Live!” took place on 27 January 2010 in Krakow and was dedicated to the 65th anniversary of the liberation of Auschwitz-Birkenau. The Forum was attended by a group of about 100 deputies from the European Parliament, headed by its President Jerzy Buzek, as well as representatives of other European institutions and official delegations from around the world.

In 2013, after hearing of the tragic fire at the Malovishersky psychoneurological nursing home in Novgorod region which killed 37 patients, Kantor launched an initiative to upgrade infrastructure and equipment at inpatient social institutions locally and across Russia. Kantor personally paid to rebuild the nursing home and a new residential center which opened its doors two years after the fire.

On 26–27 January 2015, the Fourth International “Let My People Live!” Forum was held in Prague and Terezín (Czech Republic) to mark the 70th anniversary of the liberation of Auschwitz-Birkenau concentration camp. The event was attended by several hundred distinguished guests, including heads of state, political Leaders, members of parliament, diplomats, scholars and public figures from many countries, Auschwitz-Birkenau liberators, former prisoners of the concentration camps and Holocaust survivors.

Kantor heads the publicly traded Acron Group, one of the leading mineral fertilizer producers and distributors in the world. Today, Acron is a large group of companies producing over 40 chemical products with annual output exceeding 6.5 million tonnes. In 2017, Forbes estimated Kantor's net worth at US$3.1 billion, making him the 34th richest person in Russia and the 630th richest person in the world.

In 2018, President of the Russian Academy of Arts and People’s Artist of the URSS Zurab Tsereteli officially awarded the robe and diploma of Honorary Member of the Russian Academy of Arts to President of the Museum of Avant-Garde Mastery (MAGMA) Viatcheslav Kantor.

Over several years, Kantor has been a donor to Yad Vashem, the Holocaust Martyrs' and Heroes’ Authority.