diff --git a/internal/lidarr/delete.go b/internal/lidarr/delete.go
new file mode 100644
index 00000000..2a060320
--- /dev/null
+++ b/internal/lidarr/delete.go
@@ -0,0 +1,69 @@
+package lidarr
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+// del is the shared DELETE helper. Mirrors get()/post() in client.go: builds
+// the URL inline, sets the API key, maps status codes to typed errors. The
+// caller is responsible for closing the returned body.
+func (c *Client) del(ctx context.Context, path string, q url.Values) (*http.Response, error) {
+	u, err := url.Parse(c.BaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("%w: %v", ErrUnreachable, err)
+	}
+	u.Path = strings.TrimRight(u.Path, "/") + path
+	if q != nil {
+		u.RawQuery = q.Encode()
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodDelete, u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("X-Api-Key", c.APIKey)
+
+	resp, err := c.HTTP.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("%w: %v", ErrUnreachable, err)
+	}
+	if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+		_ = resp.Body.Close()
+		return nil, ErrAuthFailed
+	}
+	if resp.StatusCode >= 500 {
+		_ = resp.Body.Close()
+		return nil, ErrServerError
+	}
+	if resp.StatusCode >= 400 {
+		_ = resp.Body.Close()
+		return nil, ErrLookupFailed
+	}
+	return resp, nil
+}
+
+// DeleteAlbum removes an album from Lidarr's library.
+//   - deleteFiles=true also removes the audio files from disk.
+//   - addImportListExclusion=true tells Lidarr to never re-add this album
+//     via import-list scans.
+//
+// M5b's admin "delete via Lidarr" action always passes both `true`.
+func (c *Client) DeleteAlbum(ctx context.Context, lidarrAlbumID int, deleteFiles, addImportListExclusion bool) error {
+	if lidarrAlbumID == 0 {
+		return fmt.Errorf("lidarr: zero album id")
+	}
+	q := url.Values{
+		"deleteFiles":            []string{strconv.FormatBool(deleteFiles)},
+		"addImportListExclusion": []string{strconv.FormatBool(addImportListExclusion)},
+	}
+	resp, err := c.del(ctx, "/api/v1/album/"+strconv.Itoa(lidarrAlbumID), q)
+	if err != nil {
+		return err
+	}
+	resp.Body.Close()
+	return nil
+}
diff --git a/internal/lidarr/delete_test.go b/internal/lidarr/delete_test.go
new file mode 100644
index 00000000..78d6789c
--- /dev/null
+++ b/internal/lidarr/delete_test.go
@@ -0,0 +1,178 @@
+package lidarr
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+)
+
+func TestLookupAlbumByMBID_HappyPath(t *testing.T) {
+	body, err := os.ReadFile("testdata/album_lookup_by_mbid.json")
+	if err != nil {
+		t.Fatalf("read fixture: %v", err)
+	}
+	c, srv := newTestClient(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/album" {
+			t.Errorf("path = %q, want /api/v1/album", r.URL.Path)
+		}
+		if got := r.URL.Query().Get("foreignAlbumId"); got != "3a2c2c8c-7e6f-4f8a-b1d2-9a8b6c4e3f1d" {
+			t.Errorf("foreignAlbumId = %q", got)
+		}
+		if got := r.Header.Get("X-Api-Key"); got != "key123" {
+			t.Errorf("X-Api-Key = %q, want key123", got)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(body)
+	})
+	defer srv.Close()
+
+	got, err := c.LookupAlbumByMBID(context.Background(), "3a2c2c8c-7e6f-4f8a-b1d2-9a8b6c4e3f1d")
+	if err != nil {
+		t.Fatalf("LookupAlbumByMBID: %v", err)
+	}
+	if got.ID != 42 || got.Title != "Music Has The Right To Children" {
+		t.Errorf("got = %+v", got)
+	}
+}
+
+func TestLookupAlbumByMBID_EmptyArrayReturnsErrNotFound(t *testing.T) {
+	c, srv := newTestClient(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("[]"))
+	})
+	defer srv.Close()
+
+	_, err := c.LookupAlbumByMBID(context.Background(), "x")
+	if !errors.Is(err, ErrNotFound) {
+		t.Errorf("err = %v, want ErrNotFound", err)
+	}
+}
+
+func TestLookupAlbumByMBID_AuthFailed(t *testing.T) {
+	c, srv := newTestClient(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+	})
+	defer srv.Close()
+
+	_, err := c.LookupAlbumByMBID(context.Background(), "x")
+	if !errors.Is(err, ErrAuthFailed) {
+		t.Errorf("err = %v, want ErrAuthFailed", err)
+	}
+}
+
+func TestLookupAlbumByMBID_5xxReturnsErrServerError(t *testing.T) {
+	c, srv := newTestClient(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+	})
+	defer srv.Close()
+
+	_, err := c.LookupAlbumByMBID(context.Background(), "x")
+	if !errors.Is(err, ErrServerError) {
+		t.Errorf("err = %v, want ErrServerError", err)
+	}
+}
+
+func TestLookupAlbumByMBID_BadJSON(t *testing.T) {
+	c, srv := newTestClient(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("not json"))
+	})
+	defer srv.Close()
+
+	_, err := c.LookupAlbumByMBID(context.Background(), "x")
+	if err == nil {
+		t.Fatal("err = nil, want decode error")
+	}
+}
+
+func TestLookupArtistByMBID_HappyPath(t *testing.T) {
+	body, err := os.ReadFile("testdata/artist_lookup_by_mbid.json")
+	if err != nil {
+		t.Fatalf("read fixture: %v", err)
+	}
+	c, srv := newTestClient(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/artist" {
+			t.Errorf("path = %q, want /api/v1/artist", r.URL.Path)
+		}
+		if got := r.URL.Query().Get("mbId"); got != "069b64b6-7884-4f6a-94cc-e4c1d6c87a01" {
+			t.Errorf("mbId = %q", got)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(body)
+	})
+	defer srv.Close()
+
+	got, err := c.LookupArtistByMBID(context.Background(), "069b64b6-7884-4f6a-94cc-e4c1d6c87a01")
+	if err != nil {
+		t.Fatalf("LookupArtistByMBID: %v", err)
+	}
+	if got.ID != 7 || got.ArtistName != "Boards of Canada" {
+		t.Errorf("got = %+v", got)
+	}
+}
+
+func TestDeleteAlbum_PassesBothFlags(t *testing.T) {
+	var captured *http.Request
+	c, srv := newTestClient(func(w http.ResponseWriter, r *http.Request) {
+		captured = r
+		w.WriteHeader(http.StatusOK)
+	})
+	defer srv.Close()
+
+	if err := c.DeleteAlbum(context.Background(), 42, true, true); err != nil {
+		t.Fatalf("DeleteAlbum: %v", err)
+	}
+	if captured == nil || captured.Method != http.MethodDelete {
+		t.Fatalf("method = %v, want DELETE", captured)
+	}
+	if captured.URL.Path != "/api/v1/album/42" {
+		t.Errorf("path = %q", captured.URL.Path)
+	}
+	if got := captured.URL.Query().Get("deleteFiles"); got != "true" {
+		t.Errorf("deleteFiles = %q", got)
+	}
+	if got := captured.URL.Query().Get("addImportListExclusion"); got != "true" {
+		t.Errorf("addImportListExclusion = %q", got)
+	}
+}
+
+func TestDeleteAlbum_5xxReturnsErrServerError(t *testing.T) {
+	c, srv := newTestClient(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+	})
+	defer srv.Close()
+
+	err := c.DeleteAlbum(context.Background(), 42, true, true)
+	if !errors.Is(err, ErrServerError) {
+		t.Errorf("err = %v, want ErrServerError", err)
+	}
+}
+
+func TestDeleteAlbum_NetworkErrorReturnsErrUnreachable(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {}))
+	srv.Close() // server is closed; client should fail to connect
+	c := NewClient(srv.URL, "test-key")
+
+	err := c.DeleteAlbum(context.Background(), 42, true, true)
+	if !errors.Is(err, ErrUnreachable) {
+		t.Errorf("err = %v, want ErrUnreachable", err)
+	}
+}
+
+func TestDeleteAlbum_ZeroIDRejected(t *testing.T) {
+	c, srv := newTestClient(func(w http.ResponseWriter, _ *http.Request) {
+		t.Error("server should not be called with zero id")
+	})
+	defer srv.Close()
+
+	if err := c.DeleteAlbum(context.Background(), 0, true, true); err == nil {
+		t.Error("err = nil, want zero-id rejection")
+	}
+}
diff --git a/internal/lidarr/errors.go b/internal/lidarr/errors.go
index 0cdf98e2..e852428f 100644
--- a/internal/lidarr/errors.go
+++ b/internal/lidarr/errors.go
@@ -10,4 +10,10 @@ var (
 	ErrLookupFailed   = errors.New("lidarr: lookup failed") // 4xx other than 401/403
 	ErrServerError    = errors.New("lidarr: server error")  // 5xx
 	ErrInvalidPayload = errors.New("lidarr: invalid payload")
+	// ErrNotFound is returned by LookupArtistByMBID and LookupAlbumByMBID
+	// when Lidarr returns 200 with an empty array — i.e., the MBID isn't in
+	// Lidarr's monitored set. Distinguished from network/auth errors so admin
+	// handlers can surface it as `lidarr_album_lookup_failed` (502) instead
+	// of `lidarr_unreachable` (503).
+	ErrNotFound = errors.New("lidarr: not found")
 )
diff --git a/internal/lidarr/lookup_mbid.go b/internal/lidarr/lookup_mbid.go
new file mode 100644
index 00000000..89e839c8
--- /dev/null
+++ b/internal/lidarr/lookup_mbid.go
@@ -0,0 +1,54 @@
+package lidarr
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/url"
+)
+
+// LookupArtistByMBID returns the artist Lidarr has indexed under that
+// MBID. Returns ErrNotFound if Lidarr returns an empty array.
+func (c *Client) LookupArtistByMBID(ctx context.Context, mbid string) (LidarrArtist, error) {
+	if mbid == "" {
+		return LidarrArtist{}, fmt.Errorf("lidarr: empty mbid")
+	}
+	q := url.Values{"mbId": []string{mbid}}
+	resp, err := c.get(ctx, "/api/v1/artist", q)
+	if err != nil {
+		return LidarrArtist{}, err
+	}
+	defer resp.Body.Close()
+
+	var rows []LidarrArtist
+	if err := json.NewDecoder(resp.Body).Decode(&rows); err != nil {
+		return LidarrArtist{}, fmt.Errorf("lidarr: decode artist: %w", err)
+	}
+	if len(rows) == 0 {
+		return LidarrArtist{}, ErrNotFound
+	}
+	return rows[0], nil
+}
+
+// LookupAlbumByMBID returns the album Lidarr has indexed under that
+// MBID. Returns ErrNotFound on empty result.
+func (c *Client) LookupAlbumByMBID(ctx context.Context, mbid string) (LidarrAlbum, error) {
+	if mbid == "" {
+		return LidarrAlbum{}, fmt.Errorf("lidarr: empty mbid")
+	}
+	q := url.Values{"foreignAlbumId": []string{mbid}}
+	resp, err := c.get(ctx, "/api/v1/album", q)
+	if err != nil {
+		return LidarrAlbum{}, err
+	}
+	defer resp.Body.Close()
+
+	var rows []LidarrAlbum
+	if err := json.NewDecoder(resp.Body).Decode(&rows); err != nil {
+		return LidarrAlbum{}, fmt.Errorf("lidarr: decode album: %w", err)
+	}
+	if len(rows) == 0 {
+		return LidarrAlbum{}, ErrNotFound
+	}
+	return rows[0], nil
+}
diff --git a/internal/lidarr/testdata/album_lookup_by_mbid.json b/internal/lidarr/testdata/album_lookup_by_mbid.json
new file mode 100644
index 00000000..90d38049
--- /dev/null
+++ b/internal/lidarr/testdata/album_lookup_by_mbid.json
@@ -0,0 +1,8 @@
+[
+  {
+    "id": 42,
+    "foreignAlbumId": "3a2c2c8c-7e6f-4f8a-b1d2-9a8b6c4e3f1d",
+    "title": "Music Has The Right To Children",
+    "artistId": 7
+  }
+]
diff --git a/internal/lidarr/testdata/artist_lookup_by_mbid.json b/internal/lidarr/testdata/artist_lookup_by_mbid.json
new file mode 100644
index 00000000..74d78984
--- /dev/null
+++ b/internal/lidarr/testdata/artist_lookup_by_mbid.json
@@ -0,0 +1,7 @@
+[
+  {
+    "id": 7,
+    "foreignArtistId": "069b64b6-7884-4f6a-94cc-e4c1d6c87a01",
+    "artistName": "Boards of Canada"
+  }
+]
diff --git a/internal/lidarr/types.go b/internal/lidarr/types.go
index d1c8ec05..8e4c8052 100644
--- a/internal/lidarr/types.go
+++ b/internal/lidarr/types.go
@@ -58,3 +58,21 @@ type AddAlbumParams struct {
 type PingResult struct {
 	Version string
 }
+
+// LidarrArtist is the subset of Lidarr's artist resource used by M5b
+// admin actions. The "id" field is Lidarr's internal numeric ID — needed
+// for DELETE /api/v1/artist/{id} calls.
+type LidarrArtist struct {
+	ID              int    `json:"id"`
+	ForeignArtistID string `json:"foreignArtistId"` // MBID
+	ArtistName      string `json:"artistName"`
+}
+
+// LidarrAlbum is the subset of Lidarr's album resource used by M5b
+// admin actions.
+type LidarrAlbum struct {
+	ID             int    `json:"id"`
+	ForeignAlbumID string `json:"foreignAlbumId"` // MBID
+	Title          string `json:"title"`
+	ArtistID       int    `json:"artistId"`
+}