| Name | Origin | Meaning | |
| Tadd | English | One of Christ's 12 apostles | Popularity of Tadd |
| Tadda | Latin | Courageous, One who praises | Popularity of Tadda |
| Taddeo | Italian | Courageous, One who praises | Popularity of Taddeo |
| Taddeo | Latin | Courageous, One who praises | Popularity of Taddeo |
| Taddy | Latin | Courageous, One who praises | Popularity of Taddy |
| Tadeo | Latin | Courageous, One who praises | Popularity of Tadeo |
| Tadeusz | Latin | Courageous, One who praises | Popularity of Tadeusz |
| Tadgh | Latin | Courageous, One who praises | Popularity of Tadgh |
| Ted | Latin | Courageous, One who praises | Popularity of Ted |
| Thad | Latin | Courageous, One who praises | Popularity of Thad |
| Thada | Latin | Courageous, One who praises | Popularity of Thada |
| Thaddaus | Latin | Courageous, One who praises | Popularity of Thaddaus |
| Thaddea | Latin | Courageous, One who praises | Popularity of Thaddea |
| Thaddeaus | Latin | Courageous, One who praises | Popularity of Thaddeaus |
| Thaddeus | English | One of Christ's 12 apostles | Popularity of Thaddeus |
| Thaddeus | Latin | Courageous, One who praises | Popularity of Thaddeus |
| Thadea | Latin | Courageous, One who praises | Popularity of Thadea |