diff --git a/.changeset/sour-knives-join.md b/.changeset/sour-knives-join.md
new file mode 100644
index 00000000..ee2bd416
--- /dev/null
+++ b/.changeset/sour-knives-join.md
@@ -0,0 +1,7 @@
+---
+"chainlink-deployments-framework": minor
+---
+
+feat(jd): new mapper function for chain family
+
+Maps JD proto ChainType to the chain selector family string
diff --git a/offchain/jd/chain_type.go b/offchain/jd/chain_type.go
new file mode 100644
index 00000000..19b23df5
--- /dev/null
+++ b/offchain/jd/chain_type.go
@@ -0,0 +1,36 @@
+package jd
+
+import (
+	"errors"
+	"fmt"
+
+	chain_selectors "github.com/smartcontractkit/chain-selectors"
+	nodev1 "github.com/smartcontractkit/chainlink-protos/job-distributor/v1/node"
+)
+
+// ChainTypeToFamily converts a JD proto ChainType to a chain selector family.
+func ChainTypeToFamily(chainType nodev1.ChainType) (string, error) {
+	var family string
+	switch chainType {
+	case nodev1.ChainType_CHAIN_TYPE_EVM:
+		family = chain_selectors.FamilyEVM
+	case nodev1.ChainType_CHAIN_TYPE_APTOS:
+		family = chain_selectors.FamilyAptos
+	case nodev1.ChainType_CHAIN_TYPE_SOLANA:
+		family = chain_selectors.FamilySolana
+	case nodev1.ChainType_CHAIN_TYPE_STARKNET:
+		family = chain_selectors.FamilyStarknet
+	case nodev1.ChainType_CHAIN_TYPE_TRON:
+		family = chain_selectors.FamilyTron
+	case nodev1.ChainType_CHAIN_TYPE_TON:
+		family = chain_selectors.FamilyTon
+	case nodev1.ChainType_CHAIN_TYPE_SUI:
+		family = chain_selectors.FamilySui
+	case nodev1.ChainType_CHAIN_TYPE_UNSPECIFIED:
+		return "", errors.New("chain type must be specified")
+	default:
+		return "", fmt.Errorf("unsupported chain type %s", chainType)
+	}
+
+	return family, nil
+}
diff --git a/offchain/jd/chain_type_test.go b/offchain/jd/chain_type_test.go
new file mode 100644
index 00000000..77e0b4cf
--- /dev/null
+++ b/offchain/jd/chain_type_test.go
@@ -0,0 +1,84 @@
+package jd
+
+import (
+	"testing"
+
+	chain_selectors "github.com/smartcontractkit/chain-selectors"
+	nodev1 "github.com/smartcontractkit/chainlink-protos/job-distributor/v1/node"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestChainTypeToFamily(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name      string
+		chainType nodev1.ChainType
+		want      string
+		wantErr   string
+	}{
+		{
+			name:      "EVM chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_EVM,
+			want:      chain_selectors.FamilyEVM,
+		},
+		{
+			name:      "Aptos chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_APTOS,
+			want:      chain_selectors.FamilyAptos,
+		},
+		{
+			name:      "Solana chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_SOLANA,
+			want:      chain_selectors.FamilySolana,
+		},
+		{
+			name:      "Starknet chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_STARKNET,
+			want:      chain_selectors.FamilyStarknet,
+		},
+		{
+			name:      "Tron chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_TRON,
+			want:      chain_selectors.FamilyTron,
+		},
+		{
+			name:      "TON chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_TON,
+			want:      chain_selectors.FamilyTon,
+		},
+		{
+			name:      "Sui chain type",
+			chainType: nodev1.ChainType_CHAIN_TYPE_SUI,
+			want:      chain_selectors.FamilySui,
+		},
+		{
+			name:      "unspecified chain type returns error",
+			chainType: nodev1.ChainType_CHAIN_TYPE_UNSPECIFIED,
+			wantErr:   "chain type must be specified",
+		},
+		{
+			name:      "invalid chain type returns error",
+			chainType: nodev1.ChainType(9999),
+			wantErr:   "unsupported chain type",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := ChainTypeToFamily(tt.chainType)
+
+			if tt.wantErr != "" {
+				require.Error(t, err)
+				require.ErrorContains(t, err, tt.wantErr)
+				assert.Empty(t, got)
+			} else {
+				require.NoError(t, err)
+				assert.Equal(t, tt.want, got)
+			}
+		})
+	}
+}