Lenny Krayzelburg is an American backstroke swimmer. Krayzelburg was born in Odessa, (formerly in the Soviet Union, now in the Ukraine), on September 28, 1975. He and his family left the Soviet Union in 1989, to look for new opportunities in the United States. They settled in Los Angeles.

In the beginning, life in the new country was tough. Lenny and his family suffered from financial difficulties and so he had to commute by bus and foot 45 minutes each way to swimming practice, and didn't get home before 9.30 in the evening. In addition, Lenny had to cope with language problems, and to study English rapidly in order to understand his coaches' instructions. Thankfully he was aided by the extensive Russian community in Los Angeles, and managed to adapt quickly.

He attended college at the University of Southern California. In 1995, he became a naturalized citizen of the United States. Three years later became the first swimmer since 1986 to sweep the backstroke events, (100 & 200m), in the world championships. Later on that month Krayzelburg broke both the 100 and the 200m world records respectively, setting the clock on 53.60 and 1.55.87. He was then recognized as the top backstroke swimmer in the world and one of the best in the history of this swimming style. He continued to dominate at the Sydney 2000 Olympics backstroke,shattering the Olympic record and nearing his own 1998 world record with 53.72 in the 100m, while making another Olympic record in the 200m with 1.56.76. He also played an important role in helping the American team win a gold medal in the 4x100m relay with a new world record of 3.33.73.

After the Olympics Krayzelburg decided to skip the 2001 World Championships that took place in Fukuoka, Japan, in order to focus on the Maccabiah games in Israel. Being Jewish, Krayzelburg wanted to take this once in a lifetime chance to compete with other top Jewish athletes. In addition, he wanted to fulfill a childhood dream by visiting the holy land and lifting the American delegacy flag during the games' opening ceremony.

A couple of months later he had to undergo surgery on his left knee, following a fall while running on a treadmill, after which he had to take a year off swimming.

In September 2003, Krazelburg split from his coach Mark Schubert, to start training under Dave Salo, who also coached Aaron Peirsol. Peirsol was considered by many to be Krayzelburg's successor. Working with Salo, Krayzelburg changed the style of his stroke, particularly due to his shoulder injuries.

This turn in Krayzelburg's career proved to be successful, He finished second in the American trials for the 100 meters event, to secure a place in the 2004 Athens Olympics, alongside training partner, Aaron Peirsol. His good shape enabled him to reach the final. He came into this final knowing this might be his career's last, gave his best effort but missed out on a medal by just 2 one hundredths of a second, with a qualitative result of 54.38, whereas Piersol won gold with 54.06. Krayzelburg made up for the upset by helping the American team to win yet another Olympic gold in the 4 x 100m relay, despite not swimming in the final of this event (he swam in the preliminary round, while Piersol took his spot in the final).

Krayzelburg is known as one of the physically strongest swimmers around, and for his powerful arm strokes that cut the water like a propellor. He is pretty tall, 1.88m high and weighs just above 85 kg.

Lenny owes lots of his career achievements to his father Oleg, who has been a significant part of his success by repeatedly urging and pushing him to go on, even when Lenny wanted to quit at the age of 14.

He speaks fluent Russian, and enjoys reading history books as well as working with computers. Additionally, he was voted as 1999's USA swimmer of the year.