diff --git a/internal/userdb/collections.go b/internal/userdb/collections.go
index 91fb8cf3..cb31a8ff 100644
--- a/internal/userdb/collections.go
+++ b/internal/userdb/collections.go
@@ -114,13 +114,53 @@ func ListCollections(db *sql.DB, profileID string) ([]Collection, error) {
 		if err := rows.Scan(&c.ID, &c.ProfileID, &c.CreatorProfileID, &c.Name, &c.CollectionType, &c.IsShared, &c.QueryDefinition, &c.SortConfig, &c.CreatedAt, &c.UpdatedAt); err != nil {
 			return nil, err
 		}
-		c.AllowedProfileIDs, err = listCollectionProfiles(db, c.ID)
-		if err != nil {
-			return nil, err
-		}
 		collections = append(collections, c)
 	}
-	return collections, rows.Err()
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if err := attachCollectionProfiles(db, profileID, collections); err != nil {
+		return nil, err
+	}
+	return collections, nil
+}
+
+// attachCollectionProfiles fills AllowedProfileIDs for every collection with a
+// single batched query, avoiding the N+1 round trip a per-collection lookup
+// would create.
+func attachCollectionProfiles(db *sql.DB, profileID string, collections []Collection) error {
+	if len(collections) == 0 {
+		return nil
+	}
+	rows, err := db.Query(
+		`SELECT allowed.collection_id, allowed.profile_id
+		 FROM personal_collection_profiles AS visible
+		 JOIN personal_collection_profiles AS allowed
+		   ON allowed.collection_id = visible.collection_id
+		 WHERE visible.profile_id = ?
+		 ORDER BY allowed.profile_id ASC`,
+		profileID,
+	)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	byCollection := make(map[string][]string, len(collections))
+	for rows.Next() {
+		var collectionID, profileID string
+		if err := rows.Scan(&collectionID, &profileID); err != nil {
+			return err
+		}
+		byCollection[collectionID] = append(byCollection[collectionID], profileID)
+	}
+	if err := rows.Err(); err != nil {
+		return err
+	}
+	for i := range collections {
+		collections[i].AllowedProfileIDs = byCollection[collections[i].ID]
+	}
+	return nil
 }
 
 // UpdateCollection renames a collection and updates its updated_at timestamp.
diff --git a/internal/userdb/listing_batch_test.go b/internal/userdb/listing_batch_test.go
new file mode 100644
index 00000000..2a11ba80
--- /dev/null
+++ b/internal/userdb/listing_batch_test.go
@@ -0,0 +1,92 @@
+package userdb
+
+import (
+	"database/sql"
+	"reflect"
+	"testing"
+
+	"github.com/Silo-Server/silo-server/internal/userstore"
+)
+
+func newListingTestDB(t *testing.T) *sql.DB {
+	t.Helper()
+	db, err := sql.Open("sqlite3", ":memory:")
+	if err != nil {
+		t.Fatalf("open sqlite: %v", err)
+	}
+	db.SetMaxOpenConns(1)
+	t.Cleanup(func() { _ = db.Close() })
+	if err := InitSchema(db); err != nil {
+		t.Fatalf("InitSchema: %v", err)
+	}
+	return db
+}
+
+func TestListProfilesAttachesAllowedLibrariesInOrder(t *testing.T) {
+	db := newListingTestDB(t)
+	for _, profile := range []Profile{
+		{ID: "p1", Name: "One", AllowedLibraryIDs: []int{5, 2}, CreatedAt: "2026-01-01T00:00:00Z"},
+		{ID: "p2", Name: "Two", AllowedLibraryIDs: []int{3}, CreatedAt: "2026-01-02T00:00:00Z"},
+		{ID: "p3", Name: "Three", CreatedAt: "2026-01-03T00:00:00Z"},
+	} {
+		if err := CreateProfile(db, profile); err != nil {
+			t.Fatalf("CreateProfile(%s): %v", profile.ID, err)
+		}
+	}
+
+	profiles, err := ListProfiles(db)
+	if err != nil {
+		t.Fatalf("ListProfiles: %v", err)
+	}
+	if len(profiles) != 3 {
+		t.Fatalf("ListProfiles returned %d profiles, want 3", len(profiles))
+	}
+	if got, want := profiles[0].AllowedLibraryIDs, []int{2, 5}; !reflect.DeepEqual(got, want) {
+		t.Fatalf("p1 AllowedLibraryIDs = %v, want %v", got, want)
+	}
+	if got, want := profiles[1].AllowedLibraryIDs, []int{3}; !reflect.DeepEqual(got, want) {
+		t.Fatalf("p2 AllowedLibraryIDs = %v, want %v", got, want)
+	}
+	if profiles[2].AllowedLibraryIDs != nil {
+		t.Fatalf("p3 AllowedLibraryIDs = %v, want nil", profiles[2].AllowedLibraryIDs)
+	}
+}
+
+func TestListCollectionsAttachesAllowedProfilesInOrder(t *testing.T) {
+	db := newListingTestDB(t)
+	collection, err := CreateCollection(db, userstore.CreateCollectionInput{
+		CreatorProfileID:  "p1",
+		Name:              "Shared",
+		IsShared:          true,
+		AllowedProfileIDs: []string{"p3", "p2"},
+	})
+	if err != nil {
+		t.Fatalf("CreateCollection: %v", err)
+	}
+
+	collections, err := ListCollections(db, "p2")
+	if err != nil {
+		t.Fatalf("ListCollections: %v", err)
+	}
+	if len(collections) != 1 || collections[0].ID != collection.ID {
+		t.Fatalf("ListCollections = %+v, want collection %s", collections, collection.ID)
+	}
+	if got, want := collections[0].AllowedProfileIDs, []string{"p1", "p2", "p3"}; !reflect.DeepEqual(got, want) {
+		t.Fatalf("AllowedProfileIDs = %v, want %v", got, want)
+	}
+}
+
+func TestBatchAttachDoesNotScaleBindParametersWithRows(t *testing.T) {
+	db := newListingTestDB(t)
+	const aboveSQLiteVariableLimit = 32767
+
+	profiles := make([]Profile, aboveSQLiteVariableLimit)
+	if err := attachAllowedLibraries(db, profiles); err != nil {
+		t.Fatalf("attachAllowedLibraries: %v", err)
+	}
+
+	collections := make([]Collection, aboveSQLiteVariableLimit)
+	if err := attachCollectionProfiles(db, "viewer", collections); err != nil {
+		t.Fatalf("attachCollectionProfiles: %v", err)
+	}
+}
diff --git a/internal/userdb/profile_libraries.go b/internal/userdb/profile_libraries.go
index 6bcd316f..0e897c98 100644
--- a/internal/userdb/profile_libraries.go
+++ b/internal/userdb/profile_libraries.go
@@ -3,6 +3,8 @@ package userdb
 import (
 	"database/sql"
 	"fmt"
+
+	"github.com/Silo-Server/silo-server/internal/userstore"
 )
 
 func listProfileAllowedLibraries(db *sql.DB, profileID string) ([]int, error) {
@@ -29,6 +31,38 @@ func listProfileAllowedLibraries(db *sql.DB, profileID string) ([]int, error) {
 	return libraryIDs, nil
 }
 
+// attachAllowedLibraries fills AllowedLibraryIDs for every profile with a
+// single batched query, avoiding the N+1 round trip a per-profile lookup
+// would create.
+func attachAllowedLibraries(db *sql.DB, profiles []Profile) error {
+	if len(profiles) == 0 {
+		return nil
+	}
+	rows, err := db.Query(
+		`SELECT profile_id, library_id
+		 FROM profile_allowed_libraries
+		 ORDER BY library_id ASC`,
+	)
+	if err != nil {
+		return fmt.Errorf("listing allowed libraries: %w", err)
+	}
+	defer rows.Close()
+
+	var allowedLibraries []userstore.ProfileAllowedLibrary
+	for rows.Next() {
+		var allowedLibrary userstore.ProfileAllowedLibrary
+		if err := rows.Scan(&allowedLibrary.ProfileID, &allowedLibrary.LibraryID); err != nil {
+			return fmt.Errorf("scanning allowed library: %w", err)
+		}
+		allowedLibraries = append(allowedLibraries, allowedLibrary)
+	}
+	if err := rows.Err(); err != nil {
+		return fmt.Errorf("iterating allowed libraries: %w", err)
+	}
+	userstore.AttachAllowedLibraries(profiles, allowedLibraries)
+	return nil
+}
+
 func replaceProfileAllowedLibrariesTx(tx *sql.Tx, profileID string, libraryIDs []int) error {
 	if _, err := tx.Exec("DELETE FROM profile_allowed_libraries WHERE profile_id = ?", profileID); err != nil {
 		return fmt.Errorf("clearing allowed libraries for profile %s: %w", profileID, err)
diff --git a/internal/userdb/profiles.go b/internal/userdb/profiles.go
index 09cf606e..54f80b0f 100644
--- a/internal/userdb/profiles.go
+++ b/internal/userdb/profiles.go
@@ -128,15 +128,14 @@ func ListProfiles(db *sql.DB) ([]Profile, error) {
 		); err != nil {
 			return nil, fmt.Errorf("scanning profile row: %w", err)
 		}
-		p.AllowedLibraryIDs, err = listProfileAllowedLibraries(db, p.ID)
-		if err != nil {
-			return nil, err
-		}
 		profiles = append(profiles, p)
 	}
 	if err := rows.Err(); err != nil {
 		return nil, fmt.Errorf("iterating profile rows: %w", err)
 	}
+	if err := attachAllowedLibraries(db, profiles); err != nil {
+		return nil, err
+	}
 	return profiles, nil
 }
 
diff --git a/internal/userstore/pgstore/profile_libraries.go b/internal/userstore/pgstore/profile_libraries.go
index 534a5b6a..f15d668c 100644
--- a/internal/userstore/pgstore/profile_libraries.go
+++ b/internal/userstore/pgstore/profile_libraries.go
@@ -6,6 +6,8 @@ import (
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgconn"
+
+	"github.com/Silo-Server/silo-server/internal/userstore"
 )
 
 type profileLibraryQuerier interface {
@@ -41,6 +43,45 @@ func listProfileAllowedLibraries(ctx context.Context, q profileLibraryQuerier, u
 	return libraryIDs, nil
 }
 
+// attachAllowedLibraries fills AllowedLibraryIDs for every profile with a
+// single batched query, avoiding the N+1 round trip a per-profile lookup
+// would create.
+func (s *PostgresUserStore) attachAllowedLibraries(ctx context.Context, profiles []userstore.Profile) error {
+	if len(profiles) == 0 {
+		return nil
+	}
+	ids := make([]string, len(profiles))
+	for i := range profiles {
+		ids[i] = profiles[i].ID
+	}
+	rows, err := s.pool.Query(ctx,
+		`SELECT profile_id, library_id
+		FROM user_profile_allowed_libraries
+		WHERE user_id = $1 AND profile_id = ANY($2)
+		ORDER BY library_id ASC`,
+		s.userID,
+		ids,
+	)
+	if err != nil {
+		return fmt.Errorf("listing allowed libraries for user %d: %w", s.userID, err)
+	}
+	defer rows.Close()
+
+	var allowedLibraries []userstore.ProfileAllowedLibrary
+	for rows.Next() {
+		var allowedLibrary userstore.ProfileAllowedLibrary
+		if err := rows.Scan(&allowedLibrary.ProfileID, &allowedLibrary.LibraryID); err != nil {
+			return fmt.Errorf("scanning allowed library for user %d: %w", s.userID, err)
+		}
+		allowedLibraries = append(allowedLibraries, allowedLibrary)
+	}
+	if err := rows.Err(); err != nil {
+		return fmt.Errorf("iterating allowed libraries for user %d: %w", s.userID, err)
+	}
+	userstore.AttachAllowedLibraries(profiles, allowedLibraries)
+	return nil
+}
+
 func replaceProfileAllowedLibraries(ctx context.Context, q profileLibraryQuerier, userID int, profileID string, libraryIDs []int) error {
 	if _, err := q.Exec(ctx,
 		"DELETE FROM user_profile_allowed_libraries WHERE user_id = $1 AND profile_id = $2",
diff --git a/internal/userstore/pgstore/profiles.go b/internal/userstore/pgstore/profiles.go
index 4131a23a..44e89fe2 100644
--- a/internal/userstore/pgstore/profiles.go
+++ b/internal/userstore/pgstore/profiles.go
@@ -126,15 +126,14 @@ func (s *PostgresUserStore) ListProfiles(ctx context.Context) ([]userstore.Profi
 		if err != nil {
 			return nil, fmt.Errorf("scanning profile row: %w", err)
 		}
-		p.AllowedLibraryIDs, err = listProfileAllowedLibraries(ctx, s.pool, s.userID, p.ID)
-		if err != nil {
-			return nil, err
-		}
 		profiles = append(profiles, *p)
 	}
 	if err := rows.Err(); err != nil {
 		return nil, fmt.Errorf("iterating profile rows: %w", err)
 	}
+	if err := s.attachAllowedLibraries(ctx, profiles); err != nil {
+		return nil, err
+	}
 	return profiles, nil
 }
 
diff --git a/internal/userstore/profile_libraries.go b/internal/userstore/profile_libraries.go
new file mode 100644
index 00000000..6e2e4235
--- /dev/null
+++ b/internal/userstore/profile_libraries.go
@@ -0,0 +1,22 @@
+package userstore
+
+// ProfileAllowedLibrary associates one profile with one allowed library.
+type ProfileAllowedLibrary struct {
+	ProfileID string
+	LibraryID int
+}
+
+// AttachAllowedLibraries replaces each profile's AllowedLibraryIDs with the
+// matching associations, preserving their input order.
+func AttachAllowedLibraries(profiles []Profile, allowedLibraries []ProfileAllowedLibrary) {
+	byProfile := make(map[string][]int, len(profiles))
+	for _, allowedLibrary := range allowedLibraries {
+		byProfile[allowedLibrary.ProfileID] = append(
+			byProfile[allowedLibrary.ProfileID],
+			allowedLibrary.LibraryID,
+		)
+	}
+	for i := range profiles {
+		profiles[i].AllowedLibraryIDs = byProfile[profiles[i].ID]
+	}
+}
diff --git a/internal/userstore/profile_libraries_test.go b/internal/userstore/profile_libraries_test.go
new file mode 100644
index 00000000..3dcce786
--- /dev/null
+++ b/internal/userstore/profile_libraries_test.go
@@ -0,0 +1,31 @@
+package userstore
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestAttachAllowedLibraries(t *testing.T) {
+	profiles := []Profile{
+		{ID: "p1", AllowedLibraryIDs: []int{99}},
+		{ID: "p2", AllowedLibraryIDs: []int{99}},
+		{ID: "p3", AllowedLibraryIDs: []int{99}},
+	}
+	allowedLibraries := []ProfileAllowedLibrary{
+		{ProfileID: "p2", LibraryID: 1},
+		{ProfileID: "p1", LibraryID: 2},
+		{ProfileID: "p1", LibraryID: 5},
+	}
+
+	AttachAllowedLibraries(profiles, allowedLibraries)
+
+	if got, want := profiles[0].AllowedLibraryIDs, []int{2, 5}; !reflect.DeepEqual(got, want) {
+		t.Fatalf("p1 AllowedLibraryIDs = %v, want %v", got, want)
+	}
+	if got, want := profiles[1].AllowedLibraryIDs, []int{1}; !reflect.DeepEqual(got, want) {
+		t.Fatalf("p2 AllowedLibraryIDs = %v, want %v", got, want)
+	}
+	if profiles[2].AllowedLibraryIDs != nil {
+		t.Fatalf("p3 AllowedLibraryIDs = %v, want nil", profiles[2].AllowedLibraryIDs)
+	}
+}