Daniel Kosakowski (born February 21, 1992) is a retired professional American tennis player. He played for the University of California, Los Angeles and was named Pacific-10 Conference 2011 Freshman Player of the Year. He resides in Downey, CA. Kosakowski spent the first two years of his professional tennis career playing in tournaments based in California, reaching the final of the USA F25 event in September 2010, eventually losing to Chris Guccione in straight sets. The following year, in June 2011, he won the USA F13 tournament, beating Steve Johnson, 6–4, 2–6, 6–3 in the final.