Germany's DAX - the most sensitive to China and trade war fears - led the way with a 2.6 percent rise to its highest level since Nov 14. The pan-European STOXX 600 climbed 1.8 percent, set for its strongest day in eight months.
US President Donald Trump and Chinese President Xi Jinping reached a truce at the G20 meeting on Saturday, halting additional tariffs and agreeing to fresh talks aimed at reaching an agreement within 90 days.
Although markets reacted positively, some investors and analysts said there remained much for the two to agree upon.
"While President Trump described the bilateral meeting with China as "amazing and productive", we believe the rivalry between the US and China will not be easily overcome, especially over the issue of intellectual property and market access," said UBS Wealth Management CIO Mark Haefele in a note.
Goldman Sachs analysts said the announcement strengthened their view that "Trump is likely to want to conclude an agreement - even if it does not include a full rollback of tariffs - well ahead of the 2020 presidential election".
Financials were the biggest driver of European shares as China-exposed bank HSBC rose and investors cheered the prospect of a end to a trade war which has dented growth.
Mining stocks led the gains and were up 5.1 percent on the news which gives China, the world's biggest metals consumer, more wiggle room in the next few months.
Antofagasta, Anglo American, and Glencore were up 6.2 to 8.6 percent.
Car stocks, which have been battered by fears of rising tariffs, jumped 4.2 percent after Trump said China agreed to cut import tariffs on American-made cars.
German carmakers Daimler, BMW, and Volkswagen climbed 4.8 to 6.2 percent, while tyre maker Continental gained 4.1 percent and Faurecia rose 6.9 percent.
Tech stocks jumped 3.1 percent with chipmakers the best-performing. Infineon, STMicroelectronics , and AMS gained 5.8 to 6.7 percent.
Overall analysts have cut their 2019 earnings growth expectations for world stocks over the past month as concern grew that a trade war would compound the impact of a slowing global economy.
The oil sector also jumped 2.7 percent as crude soared ahead of this week's OPEC meeting, expected to result in a supply cut.
Luxury stocks highly sensitive to China were also among top gainers, with heavyweight conglomerate LVMH up 5.9 percent and Gucci owner Kering rising 6.1 percent.
Away from the trade war relief, shares in French supermarkets Carrefour and Casino, underperformed after riots in Paris on Saturday.
Carrefour was down 1.1 percent and Casino was up just 0.5 percent, while France's main CAC 40 rose 2 percent.
Argenx topped the STOXX with an 11.3 percent gain after the Netherlands-based biopharma company said it signed a deal worth potentially up to $1.6 billion with Johnson & Johnson affiliate Cilag to develop its Cusatuxumab drug in certain types of cancer.