The article presents an overview of theoretical approaches to the study of the content and channels of financial contagion, the main methods and models of its quantitative analysis. The results of contemporary domestic and foreign studies devoted to the assessment of the intensity, direction and scale of contagion across countries and industries are discussed. We conclude that Russian researchers pay insufficient attention to this problem. In the practical part of the article, we test hypotheses about the transmission of contagion from the oil market to a number of Russian large companies belonging to different sectors of the economy. Sanctions and pandemic shocks are seen as external triggers for contagion. We use a large amount of oil and stock price data for a period that includes the 2014–2016 monetary and financial crisis and the 2020 pandemic crisis. To distinguish between periods of high and low market volatility, which is necessary to detect contagion, we calculate moving coefficients of variation for oil and stock prices. To identify cases of contagion, we employ the Forbes-Rigobon test, tests for coasymmetry and cocurtosis of distribution. The resulting estimates confirm numerous cases of contagion, with their number increasing as higher distribution moments are analysed. In addition, we conclude that during the 2014–2016 crisis, the Russian oil and gas industry showed the greatest vulnerability to contagion from the oil market. However, the pandemic shock changed the telecommunications sector turned out to be the most susceptible to contagion from the oil market in Russia. The banking sector in both crises showed a high degree of contagion from the oil market. At the same time, companies associated with ferrous and non-ferrous metallurgy, mining and processing of precious metals, as well as the chemical industry demonstrated the greatest resistance to financial contagion.