The player who won her last tennis Grand Slam tournament in Paris in 1999 was Steffi Graf. She claimed the title at the French Open, marking her sixth and final victory at Roland Garros. Graf defeated Martina Hingis in the final, showcasing her formidable skills and cementing her place as one of the greatest female tennis players of all time. This victory in 1999 further solidified Graf's legacy and added to her impressive collection of 22 Grand Slam singles titles throughout her illustrious career.