The storm, named Xynthia, was the worst in France since 1999 when 90 people died. Prime Minister Francois Fillon held an emergency cabinet meeting and afterward called the storm a "national catastrophe."
Many of the at least 45 victims in France drowned, while others died when hit by parts of buildings or trees and branches that were ripped off by the wind. At least a dozen people were missing Sunday and 59 others were injured.
Three people died in Spain, one was killed in Germany and a child was crushed to death in Portugal. The storm also hit Belgium, with one death reported there. Although Britain was not hit, London's Thames Barrier -- the capital's flood defense -- was closed Sunday morning as a precaution.
Nearly 900,000 people in France were without electricity. Rivers overflowed their banks in Brittany, while high tides and enormous waves swamped Atlantic Ocean communities in the early morning hours.
Sea walls broke in the town of L'Aguillon, where the ocean waters reached the roofs of some homes. Helicopters lifted people to safety throughout the day.
A retired couple who had parked their camping car on the waterfront in the town Moutier-en-Retz died when the vehicle was swallowed by rushing waters and they could not make it to firm ground.
The threat of avalanches was high in the Pyrenees Mountains and the southern Alps due to wind and wet snow. Roofs were ripped off, chimneys collapsed and the wind shattered the windows at a brewery in eastern France.
In Paris, winds knocked over motorcycles and spewed garbage around the streets of the capital. Flights were delayed and at least 100 were canceled at the two main Paris airports. A number of trains throughout France were delayed because of flooded tracks.
Winds reached about 130 mph (200 kph) on the summits of the Pyrenees and up to nearly 100 mph (160 kph) along the Atlantic Coast. The storm hit the Vendee and Charente-Maritime regions in southwestern France hardest, flooding coastal islands and tossing boats around in ports.
French President Nicolas Sarkozy and Interior Minister Brice Hortefeux planned to visit the worst hit regions Monday. The finance minister announced an easing of taxes for those affected for 2010.
The storm was moving eastward and parts of France along the border with Germany and Belgium were on alert for heavy rain and high winds.
Officials say scores of flights and trains have been canceled or delayed in southwestern Germany. One person was killed in the Black Forest area when winds brought a tree down onto his car in the Sunday afternoon storm.
Fallen trees also closed many stretches of train tracks in the states of Rhineland-Palatinate, Hesse, North Rhine-Westphalia and Saarland.
High winds caused the cancellation of 119 flights from Frankfurt airport while scores of others were delayed or diverted.
Xynthia hit Belgium in mid-afternoon. One man was killed by a falling tree in his garden in Jodoigne, southern Belgium, broadcaster VRT reported. High winds also brought down some electricity lines, leaving many without power in the south of the country.
In Spain, the interior minister said three people were killed by hurricane-strength winds and heavy rainfall that lashed the country's northern regions over the weekend. Alfredo Perez Rubalcaba said the storm had been intense in certain regions and had caused the deaths of a woman in northwestern Ourense and of two people whose car was hit by a falling tree in Arlanzon just north of Madrid.
The national weather agency had warned that a violent cyclone depression had formed over the Atlantic Ocean and was to cross areas bordering the Bay of Biscay.
Winds gusting up to 118 mph (190 kph) had blown over the Canary Islands overnight Friday causing a crane to collapse on a building, lampposts to fall onto parked cars and forcing flight cancellations.
Portugal's home affairs minister Rui Pereira said a child had been killed Saturday by a falling tree in Paredes. The 10-year-old had been playing ball near a church while waiting to go to a prayer meeting when a branch crushed him, Pereira said.