Si Simonson is listed in the credits for the following albums:
| Year | Artist | Album | Role |
|---|---|---|---|
| 1981 | Fireworks | Up | Songwriter |
| 1982 | Candle | Lullabies & Nursery Rhymes Volume 1 | Keyboards |
| 1983 | Michael James Murphy | Surrender | Songwriter |
| 1983 | 2nd Chapter of Acts | Singer Sower | Piano |
| 1985 | 2nd Chapter of Acts | Night Light | Piano |
| 1992 | 4Him | The Basics of Life | Choir Vocals |
