Pénélope Julie "Diddie" Vlasto Serpieri (8 August 1903 – 2 March 1985) was a female tennis player from France. She won the silver medal at the Paris Olympics in 1924 in women's singles, losing the final to the American Helen Wills Moody. Vlasto also won the version of the French national championships in 1924 that was open only to French nationals. She was a doubles partner of Suzanne Lenglen in many women's doubles tournaments during the early 1920s. She was born as Pénélope Julie Vlasto on 8 August 1903, in Marseille, France. According to Wallis Myers of the Daily Telegraph and Daily Mail, Vlasto was ranked in the world top ten in 1923 and 1926, reaching a career high of world No. 8 in 1923. She married Jean-Baptiste Serpieri on 17 February 1927.

Grand Slam finals

Doubles (2 titles)

Mixed doubles (1 runner-up)

Grand Slam singles tournament timeline

1Through 1923, the French Championships were open only to French nationals. The World Hard Court Championships (WHCC), actually played on clay in Paris or Brussels, began in 1912 and were open to all nationalities. The results from that tournament are shown here for 1923. The Olympics replaced the WHCC in 1924, as the Olympics were held in Paris. Beginning in 1925, the French Championships were open to all nationalities, with the results shown here beginning with that year.