Alena Sergeevna Kostornaia (Russian: ????? ????????? ?????????, born 24 August 2003) is a Russian figure skater.
She is the 2019–20 Grand Prix Final champion, the 2019 Internationaux de France champion, the 2019 NHK Trophy champion, the 2019 CS Finlandia Trophy champion and a two-time Russian national bronze medalist (2018, 2019).
On the junior level, she is the 2018 Junior World silver medalist, the 2018–19 Junior Grand Prix Final champion, the 2017–18 Junior Grand Prix Final silver medalist, and a two-time Russian junior national silver medalist (2018, 2019).
Kostornaia is the tenth woman to have successfully landed the triple Axel jump in a senior international competition.
She currently holds the world records for the highest total and short program scores as well as the junior world record for the highest short program score in ladies' skating.