Erkki Ruoslahti (born 16 February 1940 in Imatra, Finland) is a cancer researcher and distinguished professor at Sanford Burnham Prebys Medical Discovery Institute.

Ruoslahti held various academic appointments with the University of Helsinki and the University of Turku in Finland and City of Hope National Medical Center in Duarte, California until joining the La Jolla Cancer Research Foundation (now Sanford Burnham Prebys Medical Discovery Institute, or SBP) in 1979.

Ruoslahti's research group has developed a novel class of tumor-homing peptides that can be used to enhance delivery of drugs and nanoparticles to tumors.

[10][11] The prototype tumor-penetrating peptide, iRGD, is in clinical trials in solid tumor patients tested as an enhancer of cancer therapies.

[18] Recently, in vivo phage screening has been used to identify peptides that target hypertensive pulmonary arteries,[19] atherosclerosis,[20] and diseases of the brain.