Erik Rajohnson (born February 4, 1985) is a Malagasy former swimmer, who specialized in breaststroke events. He represented his nation Madagascar at the 2008 Summer Olympics, placing among the top 60 swimmers in the men's 100 m breaststroke. During his swimming career, Rajohnson trained full-time at Ostrava's sport club until his retirement from the sport in 2011 to focus on his stint as an international business development project manager for bilingual languages (French and English).
Rajohnson was invited by FINA through the Universality rule to compete for Madagascar in the men's 100 m breaststroke at the 2008 Summer Olympics in Beijing. Swimming in heat two, he posted a lifetime best of 1:08.42 to put him in fifth place and fifty-ninth overall on the evening prelims, but failed to make the cut.