A person familiar with the plans for Sunday's halftime show told The Associated Press on Thursday that Grammy winner Elliott is slated to make a surprise appearance during Perry's performance.
The person spoke to the AP on condition of anonymity because Elliott's participation had not been announced by the NFL.
Elliott was featured on a remix of Perry's song "Last Friday Night (T.G.I.F.)" in 2011.
During a news conference Thursday, Perry hinted at Elliott's involvement in the Super Bowl act, which also will feature Lenny Kravitz.
Perry said the halftime show will include an "old school" female singer — but did not say who that would be.
"When you hear the first ring of the chord," Perry promised, "I think jaws will drop and faces will melt."
Elliott is a multiplatinum rapper, singer and producer whose Grammy Awards from the early 2000s include Best Rap Solo Performance for "Get Ur Freak On," and Best Female Rap Solo Performance for "Work It" and "Scream a.k.a. Itchin'."
Other Super Bowl halftime shows have included unannounced performances, including by singer Usher and former Guns 'N Roses guitarist Slash in 2011.