US benchmark West Texas Intermediate for delivery in October jumped $1.46 to $46.13 a barrel compared with Friday's close.
Brent North Sea crude for November grew 91 cents to stand at $48.38 a barrel in late London trading.
Prices had sunk Friday after the US Federal Reserve expressed doubts about the strength of the global economy as it held off from an interest rate hike.
The Federal Reserve held its key interest rate locked near zero Thursday, citing worries about how the slowdown in China will hit the US economy.
Trading in oil in currently volatile, with prices surging in the middle of last week on easing concerns over high US supplies.
That came before the Federal Open Market Committee, the Fed's policy arm, said that "recent global economic and financial developments may restrain economic activity somewhat" and were likely to push down already tepid US inflation.
"There has been so much uncertainty surrounding the latest FOMC meeting which has caused increased volatility," for the oil market, Myrto Sokou, senior analyst at Sucden brokers, said on Monday.