Marko Aleksejev (born 14 February 1979) is a retired Estonian high jumper.

[1] He was selected to compete for the Estonian squad in the men's high jump at the 2004 Summer Olympics, and also trained throughout his athletic career for Audentese Sport Club (Estonian: Audentese Spordi Klubi) in Tallinn, under his personal coach Allan Eleranna.

[3] Aleksejev qualified for the Estonian squad in the men's high jump at the 2004 Summer Olympics in Athens.

[2] Three months before the Games, he cleared 2.27 m on his legal attempt to attain the exact Olympic B-height and assure a place on the Estonian track and field team from the European High Jump Meet in Herzogenbuchsee, Switzerland.

[4] Aleksejev elected to strenuously pass a single attempt at 2.10 and 2.15, until he could not overhaul the 2.20-metre barrier with all three misses, leaving him in a thirty-first place tie with Spain's Javier Bermejo at the end of the qualifying round.