Nicholson has been nominated 12 times and won for his leading performances in One Flew Over the Cuckoo's Nest (1975) and As Good As It Gets (1997). He also won the award for supporting actor in 1983 for Terms of Endearment.
Dustin Hoffman, who has been nominated seven times, won for his leading performances in Kramer vs. Kramer (1979) and Rain Man (1988).
Here's what Craig Zadan and Neil Meron had to say in a joint statement.
"Between the two of them, Jack Nicholson and Dustin Hoffman have created more iconic characters than any other pair of actors in the world. Their participation in this year's Oscars completes a list of presenters and performers that truly represents that great breadth and depth of acting talent in film today."
Previously announced Oscar presenters include Jane Fonda, Jennifer Garner, Kristen Stewart, Kerry Washington, Jennifer Aniston, Michael Douglas, Jamie Foxx, Paul Rudd, Salma Hayek Pinnault, Melissa McCarthy, Liam Neeson and John Travolta, Ben Affleck, Jessica Chastain, Jennifer Lawrence, Halle Berry, Sandra Bullock, Nicole Kidman and Reese Witherspoon, Mark Wahlberg, Ted, and Marvel's The Avengers cast members Robert Downey Jr., Samuel L. Jackson, Chris Evans, Jeremy Renner and Mark Ruffalo; returning 2011 Oscar winners Jean Dujardin, Christopher Plummer, Octavia Spencer and Meryl Streep; Chicago cast members Richard Gere, Queen Latifah, Renée Zellweger and Catherine Zeta-Jones; special guests Charlize Theron, Channing Tatum, Joseph Gordon-Levitt and Daniel Radcliffe; and performers including Kristin Chenoweth, Jennifer Hudson, Catherine Zeta-Jones, Hugh Jackman, Russell Crowe, Anne Hathaway, Amanda Seyfried, Eddie Redmayne, Aaron Tveit, Samantha Barks, and Helena Bonham Carter, Adele, Shirley Bassey, Norah Jones and Barbra Streisand.
Academy Awards for outstanding film achievements of 2012 will be presented on Oscar Sunday, February 24 at the Dolby Theatre at Hollywood & Highland Center®, and will be hosted by Seth MacFarlane live on the ABC Television Network. The Oscar presentation also will be televised live in more than 225 countries worldwide.