Mark Lajal (born 12 May 2003) is an Estonian tennis player. He has a career high ATP singles ranking of world No. 145, achieved on 22 September 2025. He also has a career high ATP doubles ranking of No. 703, achieved on 25 November 2024. He is currently the No. 1 Estonian player. He has won two ATP Challenger and three ITF singles titles.

Lajal represents Estonia at the Davis Cup, where he has a W/L record of 4–4.

On the junior tour, he had a career high ITF combined ranking of No. 13, achieved on 30 August 2021.

He won his first Challenger title in Little Rock, Arkansas. He became the first Estonian to win a Challenger title before his 21st birthday and Estonia’s second ever Challenger champion.

Ranked No. 229 on his ATP debut, he received a wildcard for the main draw of the 2023 European Open and defeated Jaume Munar for his first ATP win. He then lost to fourth seed and eventual finalist Arthur Fils in the second round.

As a lucky loser at the Bergamo Challenger, Lajal beat Jelle Sels, Ugo Blanchet and the opponent he lost to in qualifying, Pierre-Hugues Herbert to reach the semifinals, where he lost to David Goffin in 3 sets. As a result, he made his debut in the top 200.

In July, ranked No. 262, Lajal made his Grand Slam debut at Wimbledon after a successful qualifying campaign in which he ousted 25th qualifying seed Francesco Passaro, Henrique Rocha and fourth seed James Duckworth. He became the first Estonian man to reach a Grand Slam main draw since Jürgen Zopp at the 2018 Roland Garros. He lost in straight sets to eventual champion Carlos Alcaraz on his debut.

In August, Lajal reached his second career Challenger final in Zhangjiagang, losing to Yasutaka Uchiyama in the final.