Jim was born in Youngstown, Ohio, and later moved to New Orleans where he worked on Mardi Gras floats and as a door-to-salesman, he then moved to California where he worked odd jobs before he got into voice acting. Cummings is known for his ability to mimic Sterling Holloway's high voice.
In other television work, he provided additional voices for Robot Chicken and voiced Malefor in Season 2 of Skylanders Academy, a role that Mark Hamill originated in The Legend of Spyro: Dawn of the Dragon.
- Cummings is the third person to voice Winnie the Pooh and Kaa, after Sterling Holloway and Hal Smith.
- Not related to fellow voice actors Brian Cummings or Todd Cummings.
- He will reprise his role as Winnie the Pooh in the upcoming live action film along with Kanga, voiced by Kristen Anderson-Lopez and Roo, voiced by Wyatt Dean Hall. This makes him the second actor to reprise his animated role in a live action film, the first being James Earl Jones as Mufasa in the live action remake of The Lion King.