The companies — BP, Eni, Equinor, Repsol, Shell and TotalEnergies — generated $38bn (£28bn) between July and September alone, according to an analysis by campaign group Global Witness based on their latest quarterly financial results released this week.
Their combined profits for the nine-month period represent a 102 per cent increase on the corresponding period in 2025, highlighting the financial gains energy producers have made from the disruption to international oil and gas supplies.
The conflict began on February 28 following US and Israeli strikes on Iran, triggering significant disruption to shipping through the Strait of Hormuz, one of the world's most important energy corridors. The strategic waterway handles approximately a fifth of global oil and gas supplies.
The disruption has contributed to higher prices for crude oil, natural gas and refined petroleum products, while also improving the margins earned by oil refiners. Refining profits per barrel at Shell and TotalEnergies have nearly quadrupled compared with the same period last year.
Among the biggest beneficiaries, Shell reported adjusted earnings of $10.8bn (£8.1bn) in the third quarter, almost twice its previous level and its highest quarterly performance since 2022.
TotalEnergies also recorded a significant increase, with profits more than doubling to $9.1bn (£6.8bn) over the same period.
BP's underlying profit nearly quadrupled to $8.5bn (£6.4bn), comfortably exceeding analysts' expectations. However, the company's chief executive, Meg O'Neill, indicated that the exceptional performance might moderate, saying BP expected some easing in the fourth quarter.
Despite the substantial increase in earnings, the companies have largely directed their additional revenues towards reducing debt and rewarding shareholders rather than expanding investment in new oil and gas production.
Shell's net debt dropped to $39.7bn (£29.8bn) in the third quarter, down from $52.6bn (£39.5bn) in the first quarter. The company also reduced its capital expenditure forecast for 2026 by $1bn (£750m), bringing its expected spending to between $23bn and $25bn (£17bn-£19bn).
Similarly, TotalEnergies reduced its debt-to-equity ratio to below 10 per cent, while BP's net debt declined to $13.87bn (£10.4bn).
The surge in earnings has coincided with a sharp increase in international crude oil prices. Brent crude, the global benchmark, traded between $60 and $70 per barrel before the conflict but climbed above $100 in March.
Prices reached approximately $117 (£88) on Friday, their highest level since late April, following an attack on a tanker in the Strait of Hormuz, further intensifying concerns about the security of global energy supplies.
With no immediate resolution to the conflict in sight, uncertainty continues to hang over international oil markets.
Iran's ambassador to Pakistan has indicated that Tehran would reopen the Strait of Hormuz if Washington ended its blockade of Iranian ports. However, the United States has rejected the proposal.
Meanwhile, US Vice-President JD Vance has reportedly written to a senior Iranian official in an attempt to advance diplomatic engagement, although Iranian media reported that Tehran had not responded by Friday.
The latest figures have renewed criticism of the financial gains made by fossil fuel companies during a period of geopolitical instability and rising living costs.
Global Witness had earlier reported in May that the same six companies earned $22bn (£16.5bn) in the first three months of 2026, marking their highest quarterly profits since 2022.
In a separate assessment published in July, Oxfam projected that six of the world's largest fossil fuel companies would almost double their profits in the second quarter. The organisation also estimated that an additional tax targeting 585 oil, gas and coal companies could generate as much as $400bn (£300bn).
Jonathan Noronha-Gant of Global Witness condemned the companies' earnings, describing the profits as "obscene" against the backdrop of human suffering and economic hardship caused by the conflict.
"It is obscene that polluters are continuing to cash in on the fallout of the war in Iran, making more bumper profits from spiralling oil prices while innocent civilians suffer," he said.
"These massive profits come as ordinary people across Europe are struggling with the rising cost of living, with many struggling to afford to heat their homes as winter arrives. Oil giants can and should pay much more for the damage they are doing to our planet."
The growing debate has also placed windfall taxation back on the political agenda, particularly in Europe, where governments are under pressure to cushion households against rising energy costs.
The European Union is considering introducing a bloc-wide windfall tax on oil and gas companies, according to the EU's tax chief, Wopke Hoekstra, who disclosed the discussions to Reuters earlier this month.
Germany, Spain and four other EU member states have called for such a measure, while Portugal has already introduced a 33 per cent tax on extraordinary profits earned by oil and refining companies in 2026.
The proposal follows the EU's introduction of a similar levy in 2022 after Russia's invasion of Ukraine. In the United Kingdom, North Sea oil and gas producers are also subject to the Energy Profits Levy, a temporary windfall tax introduced that year.
Welcoming the EU's renewed interest in taxing exceptional earnings, Noronha-Gant said governments should go beyond temporary measures and introduce a permanent climate-related tax on fossil fuel companies.
"It is good news that the EU is currently considering a tax on companies' windfall profits," he said.
"But a permanent climate tax on fossil fuel companies is long overdue, this is one of the most effective tools we have to protect households from price shocks, as well as funding cheaper, cleaner renewable energy for all."
However, the oil and gas industry has opposed the proposed EU-wide levy, arguing that additional taxation could discourage investment, undermine energy security and slow the transition towards cleaner sources of energy.
The disagreement underscores the growing tension between governments seeking to shield consumers from energy price shocks and an industry insisting that maintaining investment is essential to securing future supplies and supporting the transition to a lower-carbon economy.