Murkel Alejandro Dellien Velasco (born 16 September 1997) is a Bolivian tennis player. He has a career-high ATP singles ranking of No. 263, achieved on 30 October 2023. He is the current No. 2 Bolivian tennis player. He also has a career-high ATP doubles ranking of No. 186 achieved on 29 January 2024.
Dellien played college tennis at Wichita State.
Dellien represents Bolivia at the Davis Cup, where he has a W/L record of 1–0.
In 2021 he defeated Zizou Bergs in his first Davis Cup rubber.