Lydia de Vega-Mercado (born December 12, 1964) who is a retired athlete from the Philippines, was considered Asia's fastest woman in the 1980s.
De Vega first made an impact at the 1981 Southeast Asian (SEA) Games held in Manila with gold medal performances in the 200 and 400 meter events exceeding records set at the Asian Games. As Asia's sprint queen, she ran away with the gold medal in the 100-meter dash in the 1982 New Delhi Asiad and duplicated the feat in the 1986 Seoul Asiad where she clocked 11.53 seconds.
De Vega won the gold in the 100 meters at the SEA Games (1987, 1991 and 1993). She also topped the 200 meter event in 1981, 1983, 1987 and 1993. She has twice won both the 100 and 200 meter golds in the Asian Athletics Championships - 1983 and 1987. She holds both Philippine and Southeast Asian records with her personal best of 11.28 seconds.
De Vega was a two-time Olympian, represented the Philippines at the 1984 and 1988 Summer Olympics.
She also brought home a silver medal in the 200-meter race from the 1986 Seoul Asiad, and has once represented a friend for the Long Jumps and broke her record.
In 1989 until 1991, De Vega took a break from athletics. During this period she got a degree and got married. She entered the 1991 Asian Athletics Championships and made a decent finish of seventh place.
The sprinter retired after competing at the track and field event of the 1994 Manila-Fujian Games held in October. She won the 100m event. She announced that she would not be competing at the upcoming edition of the Philippine National Games at that time.
De Vega served as a councilor of her native Meycauayan town in Bulacan province. In early 2005, she was appointed as a liaison officer of the Alliance of Coaches and Athletes of the Philippines with the Philippine Sports Commission.
In December 2005, De Vega went to Singapore after receiving three job offers from Singaporean private schools to handle athletics. She is now coaching young athletes in Singapore.
De Vega is married to Paul Mercado, a former engineer at Meralco and an entrepreneur engaged in fish pond business, to whom she had four children including Stephanie who is a former collegiate volleyball player of the DLSU Lady Spikers. In February 2001, her son John Michael who was four years old, died in a car accident.