| Regimental number | 4104 |
| Place of birth | Parramatta, New South Wales |
| School | Public School, Parramatta, New South Wales |
| Religion | Presbyterian |
| Occupation | Apprentice boilermaker |
| Address | Alfred Street, Granville, New South Wales |
| Marital status | Single |
| Age at embarkation | 19 |
| Height | 5' 5.5" |
| Weight | 135 lbs |
| Next of kin | Father, David Mills, Campbell Street, Parramatta, New South Wales |
| Previous military service | Served in 20th Junior Cadets; Served in 40th Infantry Milita, left to enlist. |
| Enlistment date | |
| Date of enlistment from Nominal Roll | |
| Rank on enlistment | Private |
| Unit name | 3rd Battalion, 12th Reinforcement |
| AWM Embarkation Roll number | 23/20/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A7 Medic on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 3rd Battalion |
| Fate | Died of wounds |
| Place of death or wounding | Flers, France |
| Age at death | 21 |
| Place of burial | Guards' Cemetery, Lesboeufs, Special Memorial 52 |
| Panel number, Roll of Honour, Australian War Memorial | 37 |
| Miscellaneous information from cemetery records | Parents: David and Elizabeth MILLS. Native of Parramatta, New South Wales |
| Family/military connections | Brother: 1582 Pte David Frank MILLS, 3rd Bn, killed in action, 27 July 1916. |
| Other details |
War service: Western Front Wounded at Pozieres, France, 22 July 1916. Medals: British War Medal, Victory Medal |
| Sources | NAA: B2455, MILLS Robert George |