| Official Name: | Arnold Line, Mississippi |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Mississippi#USA |
| Pushpin Label: | Arnold Line |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Mississippi |
| Subdivision Type2: | County |
| Subdivision Name2: | Lamar |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 4.31 |
| Area Land Km2: | 4.31 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 1.66 |
| Area Land Sq Mi: | 1.66 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Total: | 2333 |
| Population Density Km2: | 541.70 |
| Population Density Sq Mi: | 1402.89 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 213 |
| Coordinates: | 31.3353°N -89.3733°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 39401 |
| Area Code: | 601 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 666381 |
| Blank1 Name: | FIPS code |
| Blank1 Info: | 28-02060 |
Arnold Line is an unincorporated area and census-designated place (CDP) in Lamar County, Mississippi, United States. As of the 2020 census it had a population of 2,333.[2] It is part of the Hattiesburg Metropolitan Statistical Area.
It is in the northeast part of Lamar County and is bordered to the north, east, and south by the city of Hattiesburg. The center of Hattiesburg is 5miles to the east in Forrest County. West Hattiesburg is to the south of Arnold Line.
| White alone (NH) | 966 | 955 | 56.20% | 40.93% | |
| Black or African American alone (NH) | 670 | 1,118 | 38.98% | 47.92% | |
| Native American or Alaska Native alone (NH) | 1 | 2 | 0.06% | 0.09% | |
| Asian alone (NH) | 32 | 53 | 1.86% | 2.27% | |
| Pacific Islander alone (NH) | 2 | 0 | 0.12% | 0.00% | |
| Some Other Race alone (NH) | 2 | 16 | 0.12% | 0.69% | |
| Mixed Race or Multi-Racial (NH) | 12 | 78 | 0.70% | 3.34% | |
| Hispanic or Latino (any race) | 34 | 111 | 1.98% | 4.76% | |
| Total | 1,719 | 2,333 | 100.00% | 100.00% |
It is in the Lamar County School District.[5]