The 22-year-old Hollywood actress topped a poll in Glamour magazine.
The Lost In Translation star is famous for her voluptuous figure.
Glamour said: "With curves to rival Marilyn Monroe`s, Scarlett embraces old-school Hollywood style and exudes body confidence.
"Does she ever have an off day? In a word, no."
The survey of 5,000 women revealed that curvier women are the most admired.
Actress Jessica Alba was second and Brazilian supermodel Gisele Bundchen third.
Friends star Jennifer Aniston was fourth.
Angelina Jolie was fifth, followed by The OC`s Mischa Barton and Rachel Bilson, and pop stars Beyonce and Jennifer Lopez.
British actress and underwear model Kelly Brook completed the top 10.
Skinny supermodel Kate Moss languished at number 20.
The full survey results are in the May issue of Glamour, out on Thursday.
Top 20 Sexiest Bodies
1 Scarlett Johansson
2 Jessica Alba
3 Gisele Bundchen
4 Jennifer Aniston
5 Angelina Jolie
6 Mischa Barton
7 Rachel Bilson
9 Jennifer Lopez
10 Kelly Brook
11 Jessica Biel
12 Cameron Diaz
13 Sienna Miller
14 Gwen Stefani
15 Penelope Cruz
16 Kate Winslet
17 Jessica Simpson
18 Salma Hayek
19 Halle Berry
20 Kate Moss