| Km 3 | |
| Settlement Type: | Bairro |
| Mapsize: | 250px |
| Image Map1: | distrito.Sede.Santa Maria.RS.v2006.png |
| Mapsize1: | 250px |
| Map Caption1: | District of Sede, in Santa Maria City, Rio Grande do Sul, Brazil |
| Coordinates: | -29.6887°N -53.7736°W |
| Subdivision Type: | Country |
| Subdivision Name: | Brazil |
| Subdivision Type1: | State |
| Subdivision Name1: | Rio Grande do Sul |
| Subdivision Type2: | Municipality/City |
| Subdivision Name2: | Santa Maria |
| Subdivision Type3: | District |
| Subdivision Name3: | District of Sede |
| Area Total Km2: | 3.4878 |
| Area Total Sq Mi: | 1.3466 |
| Population Footnotes: | [1] |
| Population Total: | 2504 |
| Population Density Km2: | auto |
| Population Density Sq Mi: | auto |
| Postal Code: | 97.090-090 to 97.095-709 |
| Blank1 Name Sec1: | Adjacent bairros |
| Blank1 Info Sec1: | Arroio Grande, Campestre do Menino Deus, Cerrito, Nossa Senhora das Dores, Pé de Plátano, Presidente João Goulart, São José. |
| Website: | Official site of Santa Maria |
Km 3[2] (pronounced as /pt/, "Km 3") is a Bairro in the District of Sede in the municipality of Santa Maria, in the Brazilian state of Rio Grande do Sul. It is located in northeast Santa Maria.
The bairro contains the following villages: Km 3, Vila Anacleto Corrêa, Vila Bilibiu, Vila Dr. Wautier, Vila Favarin, Vila Palmares.