Rebecca Llewellyn (born 5 October 1985) is a retired tennis player from Wales.

In her career, she won one title in singles and seven in doubles on the ITF Women's Circuit.

In terms of Grand Slam success, her best singles result came at Wimbledon in 2000 when she won two matches to qualify and then went on to reach the second round.

Rebecca competed in doubles at a Grand Slam only once, at the 2001 Wimbledon Championships, where she and compatriot Katie O'Brien were knocked out in round one.

[2] Llewellyn took part in the 2005 Wimbledon Championships, but lost 0–6, 1–6 to the fifth seed Svetlana Kuznetsova.