Modeling conducted by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington's School of Medicine showed that approximately 151,680 people were likely to die from the virus across the continent.
While the novel coronavirus emerged in China and was initially focused in east Asia, the World Health Organization now says the pandemic is centered in western Europe, with Spain, Italy and France experiencing devastating death tolls.
Most European nations have introduced strict social distancing measures to try to stem the virus spread.
More than 5,000 people have died from COVID-19 in Britain, fewer than in Spain, Italy and France.
But Britain's epidemic lags behind the rest of the continent by several days, and its death toll trajectory is already steeper than other nations.
Using local and international data on case numbers, as well as age mortality breakdowns from Italy, China and the US, the team at IHME modeled the expected death toll on a country-by-country basis.
A key consideration was an individual nation's intensive care bed capacity.
It found that Britain could experience 66,000 COVID-19 deaths by July, far more than Italy, the next most severely impacted, with around 20,000.
Spain and France were next, with 19,000 and 15,000 predicted deaths, respectively.
"We are expecting a foreboding few weeks for people in many parts of Europe," said IHME Director Christopher Murray.
"It seems likely the number of deaths will exceed our projections for the United States."
On Sunday the institute predicted just over 80,000 US COVID-19 deaths during the pandemic's first wave.
The modeling suggests that outbreaks in Italy and Spain, where hundreds of deaths have been reported daily for weeks, may be past their peak.
Daily deaths in both countries have declined for several days.
But Britain is likely weeks away from getting a handle on its death toll as intensive care capacity is overwhelmed.
Peak demand was forecast to see more than 100,000 hospital beds needed versus the 17,765 currently available.
- Could still get worse -
Prime Minister Boris Johnson, who is currently in intensive care with COVID-19, came in for criticism for his government's slow response to the pandemic.
Britain now has strict social distancing measures in place, but it had held off implementing them even as the outbreak surged in Europe.
The IHME models include the predicted effect of social distancing, and Murray said it was vital that measures aren't relaxed too suddenly once countries pass their morality peak.
"It is unequivocally evident that social distancing can, when well implemented and maintained, control the epidemic, leading to declining death rates," Murray said.
"Those nations hit hard early on implemented social distancing orders and may have the worst behind them as they are seeing important progress in reducing their death rates.
"Each nation's trajectory will change -- and dramatically for the worse -- if people ease up on social distancing or relax other precautions."