Mariia Sergeevna Tkacheva (; born 17 December 2001) is a Russian tennis player.
Tkacheva has career-high rankings by the WTA of 319 singles and 362 in doubles, achieved November 2024 and November 2022, respectively. She has won six singles and 12 doubles tournaments on the ITF Women's World Tennis Tour.
Tkacheva won her biggest title to date at the 2022 President's Cup, where she partnered Anastasia Zolotareva to win the doubles tournament.
She made her WTA Tour debut at the 2022 Chennai Open, losing to Varvara Gracheva in the first round.