Inspiraciju za stvaranje likova su kao i za stvaranje same serije uzeli iz realnog života. Neki likovi su čak zadržali svoja prava imena u seriji kao npr. Kramer,Constanza i sam Jerry o čijem životu se radi u seriji.
| Lik u seriji | Glumac | Sezona | ||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| Main | ||||||||
| Jerry Seinfeld | Jerry Seinfeld | Main | ||||||
| George Costanza | Jason Alexander | Main | ||||||
| Elaine Benes | Julia Louis-Dreyfus | Main | ||||||
| Cosmo Kramer | Michael Richards | Main | ||||||
| Recurring | ||||||||
| Morty Seinfeld | Barney Martin | Guest | Recurring | |||||
| Helen Seinfeld | Liz Sheridan | Guest | Recurring | |||||
| Newman | Wayne Knight | Guest | Recurring | |||||
| Uncle Leo | Len Lesser | Guest | Guest | Recurring | Guest | Guest | Recurring | |
| Susan Ross | Heidi Swedberg | Recurring | Recurring | Guest | ||||
| Ruthie Cohen | Ruth Cohen | Recurring | ||||||
| Frank Costanza | Jerry Stiller | Guest | Recurring | |||||
| Estelle Costanza | Estelle Harris | Recurring | ||||||
| George Steinbrenner | Larry David (voice), Mitch Mitchell & Lee Bear (body) | Guest | Recurring | Guest | ||||
| Mr. Wilhelm | Richard Herd | Recurring | Guest | |||||
| Jacopo Peterman | John O’Hurley | Guest | Recurring |
Seinfeld 