Meet organizers announced Powell's participation Wednesday in the 100 against Bolt, who confirmed in January he would run.
Both runners will be making their season debuts in the lucrative Diamond League.
Since Powell set a world record of 9.74 seconds in Rieti, Italy, in 2007, Bolt has broken the mark three times, the last being a 9.58 at the 2009 world championships in Berlin.
Other entries for the annual meet at the 80,000-seat Stadio Olimpico include American sprinters Allyson Felix and Sanya Richards, the world champions in the 200 and 400, respectively. Organizers said the pair will run both the 200 and 400.
Also attending will be 800 world record holder David Rudisha of Kenya.