The Breakthrough of the Year is an annual award made by the journal Science for the most significant development in scientific research. It originated in 1989 as "the molecule of the year", inspired by Time's Man of the Year. It was renamed the "Breakthrough of the year" in 1996.

• 1989 PCR and DNA polymerase
• 1990 the manufacture of synthetic diamonds
• 1991 buckminsterfullerene
• 1992 nitric oxide
• 1993 p53
• 1994 DNA repair enzyme
• 1995 Bose?Einstein condensate
• 1996 understanding HIV
• 1997 Dolly the sheep, the first mammal to be cloned from adult cells
• 1998 the accelerating universe, dark matter
• 1999 capturing the promise of youth with stem cells
• 2000 genomics
• 2001 nanocircuits or molecular circuit
• 2002 small RNAs
• 2003 dark energy
• 2004 Mars
• 2005 evolution in action
• 2006 proof of the Poincaré conjecture
• 2007 Human genetic variation