Family name Sirmacis (Sirmacis 
) , worldwide, is a very rare cognomen. The family name Sirmacis is habitual in Northern Europe, particularly Latvia, where it is a rare surname.
| VARIANT | COUNTRY |
|---|---|
| Sirmacis | Latvia |
| ralfs sirmacis Latvian rally driver, LV (b. 1994) |
|