Valmiki was Brahmin by birth.

Padma Purana 5:66:143-146a. Once the brāhmaṇa Vālmīki went to a great forest where there were tāla (trees), tamāla (trees) and blossomed kiṃśuka (trees); where ketakī (tree) made the forest fragrant with its pollen and was seen like the great lustre of the moon by having white heads; where there were many blossomed trees like campaka, bakula, and kovidāra and kuraṇṭaka. The forest sounded with the notes of cuckoos and the hummings of bees; it was charming everywhere and full of lovely birds.

 

Skanda Purana V.i.24.3-4 “O Vyasa, formerly there was a Brahmana named Sumati, born in the family of Bhrigu. His wife Kausiki was richly endowed with beauty and youth. A son was born to him named Agnisarman(Valmiki)…”

 

Vishnu Puarna:-Haryátmá; in the twenty-second, Veńa, who is likewise named Rájaśravas; in the twenty-third, Somaśushmápańa, also Trińavindu; in the twenty-fourth, Riksha, the descendant of Bhrigu, who is known also by the name Válmíki;

Valmiki was Brahmin by birth.

Padma Purana 5:66:143-146a. Once the brāhmaṇa Vālmīki went to a great forest where there were tāla (trees), tamāla (trees) and blossomed kiṃśuka (trees); where ketakī (tree) made the forest fragrant with its pollen and was seen like the great lustre of the moon by having white heads; where there were many blossomed trees like campaka, bakula, and kovidāra and kuraṇṭaka. The forest sounded with the notes of cuckoos and the hummings of bees; it was charming everywhere and full of lovely birds.

Skanda Purana V.i.24.3-4 “O Vyasa, formerly there was a Brahmana named Sumati, born in the family of Bhrigu. His wife Kausiki was richly endowed with beauty and youth. A son was born to him named Agnisarman(Valmiki)…”

Vishnu Puarna:-Haryátmá; in the twenty-second, Veńa, who is likewise named Rájaśravas; in the twenty-third, Somaśushmápańa, also Trińavindu; in the twenty-fourth, Riksha, the descendant of Bhrigu, who is known also by the name Válmíki;

Valmiki was Brahmin by birth.

143-146a. Once the brāhmaṇa Vālmīki went to a great forest where there were tāla (trees), tamāla (trees) and blossomed kiṃśuka (trees); where ketakī (tree) made the forest fragrant with its pollen and was seen like the great lustre of the moon by having white heads; where there were many blossomed trees like campaka, bakula, and kovidāra and kuraṇṭaka. The forest sounded with the notes of cuckoos and the hummings of bees; it was charming everywhere and full of lovely birds.

https://www.wisdomlib.org/hinduism/book/the-padma-purana/d/doc365377.html

Skanda Purana V.i.24.3-4 “O Vyasa, formerly there was a Brahmana named Sumati, born in the family of Bhrigu. His wife Kausiki was richly endowed with beauty and youth. A son was born to him named Agnisarman(Valmiki)…”

Valmiki was Brahmin by birth.

Padma Purana 5:66:143-146a. Once the brāhmaṇa Vālmīki went to a great forest where there were tāla (trees), tamāla (trees) and blossomed kiṃśuka (trees); where ketakī (tree) made the forest fragrant with its pollen and was seen like the great lustre of the moon by having white heads; where there were many blossomed trees like campaka, bakula, and kovidāra and kuraṇṭaka. The forest sounded with the notes of cuckoos and the hummings of bees; it was charming everywhere and full of lovely birds.

Skanda Purana V.i.24.3-4 “O Vyasa, formerly there was a Brahmana named Sumati, born in the family of Bhrigu. His wife Kausiki was richly endowed with beauty and youth. A son was born to him named Agnisarman(Valmiki)…”

Vishnu Puarna:-Haryátmá; in the twenty-second, Veńa, who is likewise named Rájaśravas; in the twenty-third, Somaśushmápańa, also Trińavindu; in the twenty-fourth, Riksha, the descendant of Bhrigu, who is known also by the name Válmíki;