diff --git a/Documentation/git-backfill.adoc b/Documentation/git-backfill.adoc
index c0a3b80615..82d6a1969d 100644
--- a/Documentation/git-backfill.adoc
+++ b/Documentation/git-backfill.adoc
@@ -80,6 +80,10 @@ OPTIONS
 +
 You may also use commit-limiting options understood by
 linkgit:git-rev-list[1] such as `--first-parent`, `--since`, or pathspecs.
++
+Most `--filter=<spec>` options don't work with the purpose of
+`git backfill`, but the `sparse:<oid>` filter is integrated to provide a
+focused set of paths to download, distinct from the `--sparse` option.
 
 SEE ALSO
 --------
diff --git a/Documentation/git-pack-objects.adoc b/Documentation/git-pack-objects.adoc
index 85ae48b699..e38853391b 100644
--- a/Documentation/git-pack-objects.adoc
+++ b/Documentation/git-pack-objects.adoc
@@ -404,7 +404,8 @@ will be automatically changed to version `1`.
 +
 Incompatible with `--delta-islands`. The `--use-bitmap-index` option is
 ignored in the presence of `--path-walk`. The `--path-walk` option
-supports the `--filter=<spec>` forms `blob:none` and `blob:limit=<n>`.
+supports the `--filter=<spec>` forms `blob:none`, `blob:limit=<n>`, and
+`sparse:<oid>`.
 
 
 DELTA ISLANDS
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index bc9fb5b457..b783dc62bc 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -4754,7 +4754,7 @@ static int add_objects_by_path(const char *path,
 	return 0;
 }
 
-static void get_object_list_path_walk(struct rev_info *revs)
+static int get_object_list_path_walk(struct rev_info *revs)
 {
 	struct path_walk_info info = PATH_WALK_INFO_INIT;
 	unsigned int processed = 0;
@@ -4777,8 +4777,9 @@ static void get_object_list_path_walk(struct rev_info *revs)
 	result = walk_objects_by_path(&info);
 	trace2_region_leave("pack-objects", "path-walk", revs->repo);
 
-	if (result)
-		die(_("failed to pack objects via path-walk"));
+	path_walk_info_clear(&info);
+
+	return result;
 }
 
 static void get_object_list(struct rev_info *revs, struct strvec *argv)
@@ -4841,8 +4842,13 @@ static void get_object_list(struct rev_info *revs, struct strvec *argv)
 		fn_show_object = show_object;
 
 	if (path_walk) {
-		get_object_list_path_walk(revs);
-	} else {
+		if (get_object_list_path_walk(revs)) {
+			warning(_("failed to pack objects via path-walk"));
+			path_walk = 0;
+		}
+	}
+
+	if (!path_walk) {
 		if (prepare_revision_walk(revs))
 			die(_("revision walk setup failed"));
 		mark_edges_uninteresting(revs, show_edge, sparse);
diff --git a/path-walk.c b/path-walk.c
index 225857bbc8..ce38dcf1e9 100644
--- a/path-walk.c
+++ b/path-walk.c
@@ -10,6 +10,7 @@
 #include "hex.h"
 #include "list-objects.h"
 #include "list-objects-filter-options.h"
+#include "object-name.h"
 #include "odb.h"
 #include "object.h"
 #include "oid-array.h"
@@ -180,10 +181,6 @@ static int add_tree_entries(struct path_walk_context *ctx,
 			return -1;
 		}
 
-		/* Skip this object if already seen. */
-		if (o->flags & SEEN)
-			continue;
-
 		strbuf_setlen(&path, base_len);
 		strbuf_add(&path, entry.path, entry.pathlen);
 
@@ -194,6 +191,40 @@ static int add_tree_entries(struct path_walk_context *ctx,
 		if (type == OBJ_TREE)
 			strbuf_addch(&path, '/');
 
+		if (o->flags & SEEN) {
+			/*
+			 * A tree with a shared OID may appear at multiple
+			 * paths. Even though we already added this tree to
+			 * the output at some other path, we still need to
+			 * walk into it at this in-cone path to discover
+			 * blobs that were not found at the earlier
+			 * out-of-cone path.
+			 *
+			 * Only do this for paths not yet in our map, to
+			 * avoid duplicate entries when the same tree OID
+			 * appears at the same path across multiple commits.
+			 */
+			if (type == OBJ_TREE && ctx->info->pl &&
+			    ctx->info->pl->use_cone_patterns &&
+			    !ctx->info->pl_sparse_trees &&
+			    !strmap_contains(&ctx->paths_to_lists, path.buf)) {
+				int dtype;
+				enum pattern_match_result m;
+				m = path_matches_pattern_list(path.buf, path.len,
+							      path.buf + base_len,
+							      &dtype,
+							      ctx->info->pl,
+							      ctx->repo->index);
+				if (m != NOT_MATCHED) {
+					add_path_to_list(ctx, path.buf, type,
+							 &entry.oid,
+							 !(o->flags & UNINTERESTING));
+					push_to_stack(ctx, path.buf);
+				}
+			}
+			continue;
+		}
+
 		if (ctx->info->pl) {
 			int dtype;
 			enum pattern_match_result match;
@@ -544,6 +575,48 @@ static int prepare_filters(struct path_walk_info *info,
 		}
 		return 1;
 
+	case LOFC_SPARSE_OID:
+		if (info) {
+			struct object_id sparse_oid;
+			struct repository *repo = info->revs->repo;
+
+			if (info->pl) {
+				warning(_("sparse filter cannot be combined with existing sparse patterns"));
+				return 0;
+			}
+
+			if (repo_get_oid_with_flags(repo,
+						    options->sparse_oid_name,
+						    &sparse_oid,
+						    GET_OID_BLOB)) {
+				error(_("unable to access sparse blob in '%s'"),
+				      options->sparse_oid_name);
+				return 0;
+			}
+
+			CALLOC_ARRAY(info->pl, 1);
+			info->pl->use_cone_patterns = 1;
+
+			if (add_patterns_from_blob_to_list(&sparse_oid, "", 0,
+							   info->pl) < 0) {
+				clear_pattern_list(info->pl);
+				FREE_AND_NULL(info->pl);
+				error(_("unable to parse sparse filter data in '%s'"),
+				      oid_to_hex(&sparse_oid));
+				return 0;
+			}
+
+			if (!info->pl->use_cone_patterns) {
+				clear_pattern_list(info->pl);
+				FREE_AND_NULL(info->pl);
+				warning(_("sparse filter is not cone-mode compatible"));
+				return 0;
+			}
+
+			list_objects_filter_release(options);
+		}
+		return 1;
+
 	default:
 		error(_("object filter '%s' not supported by the path-walk API"),
 		      list_objects_filter_spec(options));
diff --git a/t/t5317-pack-objects-filter-objects.sh b/t/t5317-pack-objects-filter-objects.sh
index 501d715b9a..dddb79ba62 100755
--- a/t/t5317-pack-objects-filter-objects.sh
+++ b/t/t5317-pack-objects-filter-objects.sh
@@ -478,4 +478,129 @@ test_expect_success 'verify pack-objects w/ --missing=allow-any' '
 	EOF
 '
 
+# Test that --path-walk produces the same object set as standard traversal
+# when using sparse:oid filters with cone-mode patterns.
+#
+# The sparse:oid filter restricts only blobs, not trees. Both standard
+# and path-walk should produce identical sets of blobs, commits, and trees.
+
+test_expect_success 'setup pw_sparse for path-walk comparison' '
+	git init pw_sparse &&
+	mkdir -p pw_sparse/inc/sub pw_sparse/exc/sub &&
+
+	for n in 1 2
+	do
+		echo "inc $n" >pw_sparse/inc/file$n &&
+		echo "inc sub $n" >pw_sparse/inc/sub/file$n &&
+		echo "exc $n" >pw_sparse/exc/file$n &&
+		echo "exc sub $n" >pw_sparse/exc/sub/file$n &&
+		echo "root $n" >pw_sparse/root$n || return 1
+	done &&
+
+	git -C pw_sparse add . &&
+	git -C pw_sparse commit -m "first" &&
+
+	echo "inc 1 modified" >pw_sparse/inc/file1 &&
+	echo "exc 1 modified" >pw_sparse/exc/file1 &&
+	echo "root 1 modified" >pw_sparse/root1 &&
+	git -C pw_sparse add . &&
+	git -C pw_sparse commit -m "second" &&
+
+	# Cone-mode sparse pattern: include root + inc/
+	printf "/*\n!/*/\n/inc/\n" |
+	git -C pw_sparse hash-object -w --stdin >sparse_oid
+'
+
+test_expect_success 'sparse:oid with --path-walk produces same blobs' '
+	oid=$(cat sparse_oid) &&
+
+	git -C pw_sparse pack-objects --revs --stdout \
+		--filter=sparse:oid=$oid >standard.pack <<-EOF &&
+	HEAD
+	EOF
+	git -C pw_sparse index-pack ../standard.pack &&
+	git -C pw_sparse verify-pack -v ../standard.pack >standard_verify &&
+
+	git -C pw_sparse pack-objects --revs --stdout \
+		--path-walk --filter=sparse:oid=$oid >pathwalk.pack <<-EOF &&
+	HEAD
+	EOF
+	git -C pw_sparse index-pack ../pathwalk.pack &&
+	git -C pw_sparse verify-pack -v ../pathwalk.pack >pathwalk_verify &&
+
+	# Blobs must match exactly
+	grep -E "^[0-9a-f]{40} blob" standard_verify |
+	awk "{print \$1}" | sort >standard_blobs &&
+	grep -E "^[0-9a-f]{40} blob" pathwalk_verify |
+	awk "{print \$1}" | sort >pathwalk_blobs &&
+	test_cmp standard_blobs pathwalk_blobs &&
+
+	# Commits must match exactly
+	grep -E "^[0-9a-f]{40} commit" standard_verify |
+	awk "{print \$1}" | sort >standard_commits &&
+	grep -E "^[0-9a-f]{40} commit" pathwalk_verify |
+	awk "{print \$1}" | sort >pathwalk_commits &&
+	test_cmp standard_commits pathwalk_commits
+'
+
+test_expect_success 'sparse:oid with --path-walk includes all trees' '
+	# The sparse:oid filter restricts only blobs, not trees.
+	# Both standard and path-walk should include the same trees.
+	grep -E "^[0-9a-f]{40} tree" standard_verify |
+	awk "{print \$1}" | sort >standard_trees &&
+	grep -E "^[0-9a-f]{40} tree" pathwalk_verify |
+	awk "{print \$1}" | sort >pathwalk_trees &&
+
+	test_cmp standard_trees pathwalk_trees
+'
+
+# Test the edge case where the same tree/blob OID appears at both an
+# in-cone and out-of-cone path. When sibling directories have identical
+# contents, they share a tree OID. The path-walk defers marking objects
+# SEEN until after checking sparse patterns, so an object at an out-of-cone
+# path can still be discovered at an in-cone path.
+
+test_expect_success 'setup pw_shared for shared OID across cone boundary' '
+	git init pw_shared &&
+	mkdir pw_shared/aaa pw_shared/zzz &&
+	echo "shared content" >pw_shared/aaa/file &&
+	echo "shared content" >pw_shared/zzz/file &&
+	echo "root file" >pw_shared/rootfile &&
+	git -C pw_shared add . &&
+	git -C pw_shared commit -m "aaa and zzz share tree OID" &&
+
+	# Verify they share a tree OID
+	aaa_tree=$(git -C pw_shared rev-parse HEAD:aaa) &&
+	zzz_tree=$(git -C pw_shared rev-parse HEAD:zzz) &&
+	test "$aaa_tree" = "$zzz_tree" &&
+
+	# Cone pattern: include root + zzz/ (not aaa/)
+	printf "/*\n!/*/\n/zzz/\n" |
+	git -C pw_shared hash-object -w --stdin >shared_sparse_oid
+'
+
+test_expect_success 'shared tree OID: --path-walk blobs match standard' '
+	oid=$(cat shared_sparse_oid) &&
+
+	git -C pw_shared pack-objects --revs --stdout \
+		--filter=sparse:oid=$oid >shared_std.pack <<-EOF &&
+	HEAD
+	EOF
+	git -C pw_shared index-pack ../shared_std.pack &&
+	git -C pw_shared verify-pack -v ../shared_std.pack >shared_std_verify &&
+
+	git -C pw_shared pack-objects --revs --stdout \
+		--path-walk --filter=sparse:oid=$oid >shared_pw.pack <<-EOF &&
+	HEAD
+	EOF
+	git -C pw_shared index-pack ../shared_pw.pack &&
+	git -C pw_shared verify-pack -v ../shared_pw.pack >shared_pw_verify &&
+
+	grep -E "^[0-9a-f]{40} blob" shared_std_verify |
+	awk "{print \$1}" | sort >shared_std_blobs &&
+	grep -E "^[0-9a-f]{40} blob" shared_pw_verify |
+	awk "{print \$1}" | sort >shared_pw_blobs &&
+	test_cmp shared_std_blobs shared_pw_blobs
+'
+
 test_done
diff --git a/t/t6601-path-walk.sh b/t/t6601-path-walk.sh
index 02ad83dfb0..ac294867a5 100755
--- a/t/t6601-path-walk.sh
+++ b/t/t6601-path-walk.sh
@@ -596,4 +596,135 @@ test_expect_success 'all, blob:limit=3 filter' '
 	test_cmp_sorted expect out
 '
 
+test_expect_success 'setup sparse filter blob' '
+	# Cone-mode patterns: include root, exclude all dirs, include left/
+	cat >patterns <<-\EOF &&
+	/*
+	!/*/
+	/left/
+	EOF
+	sparse_oid=$(git hash-object -w -t blob patterns)
+'
+
+test_expect_success 'all, sparse:oid filter' '
+	test-tool path-walk --filter=sparse:oid=$sparse_oid -- --all >out &&
+
+	cat >expect <<-EOF &&
+	0:commit::$(git rev-parse topic)
+	0:commit::$(git rev-parse base)
+	0:commit::$(git rev-parse base~1)
+	0:commit::$(git rev-parse base~2)
+	1:tag:/tags:$(git rev-parse refs/tags/first)
+	1:tag:/tags:$(git rev-parse refs/tags/second.1)
+	1:tag:/tags:$(git rev-parse refs/tags/second.2)
+	1:tag:/tags:$(git rev-parse refs/tags/third)
+	1:tag:/tags:$(git rev-parse refs/tags/fourth)
+	1:tag:/tags:$(git rev-parse refs/tags/tree-tag)
+	1:tag:/tags:$(git rev-parse refs/tags/blob-tag)
+	2:blob:/tagged-blobs:$(git rev-parse refs/tags/blob-tag^{})
+	2:blob:/tagged-blobs:$(git rev-parse refs/tags/blob-tag2^{})
+	3:tree::$(git rev-parse topic^{tree})
+	3:tree::$(git rev-parse base^{tree})
+	3:tree::$(git rev-parse base~1^{tree})
+	3:tree::$(git rev-parse base~2^{tree})
+	3:tree::$(git rev-parse refs/tags/tree-tag^{})
+	3:tree::$(git rev-parse refs/tags/tree-tag2^{})
+	4:blob:a:$(git rev-parse base~2:a)
+	5:blob:file2:$(git rev-parse refs/tags/tree-tag2^{}:file2)
+	6:tree:a/:$(git rev-parse base:a)
+	7:tree:child/:$(git rev-parse refs/tags/tree-tag:child)
+	8:tree:left/:$(git rev-parse base:left)
+	8:tree:left/:$(git rev-parse base~2:left)
+	9:blob:left/b:$(git rev-parse base~2:left/b)
+	9:blob:left/b:$(git rev-parse base:left/b)
+	10:tree:right/:$(git rev-parse topic:right)
+	10:tree:right/:$(git rev-parse base~1:right)
+	10:tree:right/:$(git rev-parse base~2:right)
+	blobs:6
+	commits:4
+	tags:7
+	trees:13
+	EOF
+
+	test_cmp_sorted expect out
+'
+
+test_expect_success 'topic only, sparse:oid filter' '
+	test-tool path-walk --filter=sparse:oid=$sparse_oid -- topic >out &&
+
+	cat >expect <<-EOF &&
+	0:commit::$(git rev-parse topic)
+	0:commit::$(git rev-parse base~1)
+	0:commit::$(git rev-parse base~2)
+	1:tree::$(git rev-parse topic^{tree})
+	1:tree::$(git rev-parse base~1^{tree})
+	1:tree::$(git rev-parse base~2^{tree})
+	2:blob:a:$(git rev-parse base~2:a)
+	3:tree:left/:$(git rev-parse base~2:left)
+	4:blob:left/b:$(git rev-parse base~2:left/b)
+	5:tree:right/:$(git rev-parse topic:right)
+	5:tree:right/:$(git rev-parse base~1:right)
+	5:tree:right/:$(git rev-parse base~2:right)
+	blobs:2
+	commits:3
+	tags:0
+	trees:7
+	EOF
+
+	test_cmp_sorted expect out
+'
+
+# Demonstrate the SEEN flag ordering issue: when the same tree/blob OID
+# appears at two sibling paths where one is in-cone and the other is
+# out-of-cone, the path-walk must still discover blobs at the in-cone
+# path even when the shared tree OID was first encountered out-of-cone.
+# Since sparse:oid includes all trees, the out-of-cone tree (aaa/) is
+# walked first, and its blob is skipped. The path-walk then re-walks
+# the same tree OID at the in-cone path (zzz/) to find the blob there.
+
+test_expect_success 'setup shared tree OID across cone boundary' '
+	git checkout --orphan shared-tree &&
+	git rm -rf . &&
+	mkdir aaa zzz &&
+	echo "shared content" >aaa/file &&
+	echo "shared content" >zzz/file &&
+	echo "root file" >rootfile &&
+	git add aaa zzz rootfile &&
+	git commit -m "aaa and zzz have same tree OID" &&
+
+	# Verify they really share a tree OID
+	aaa_tree=$(git rev-parse HEAD:aaa) &&
+	zzz_tree=$(git rev-parse HEAD:zzz) &&
+	test "$aaa_tree" = "$zzz_tree" &&
+
+	# Cone pattern: include root + zzz/ (not aaa/)
+	cat >shared-patterns <<-\EOF &&
+	/*
+	!/*/
+	/zzz/
+	EOF
+	shared_sparse_oid=$(git hash-object -w -t blob shared-patterns)
+'
+
+test_expect_success 'sparse:oid with shared tree OID across cone boundary' '
+	test-tool path-walk \
+		--filter=sparse:oid=$shared_sparse_oid \
+		-- shared-tree >out &&
+
+	cat >expect <<-EOF &&
+	0:commit::$(git rev-parse shared-tree)
+	1:tree::$(git rev-parse shared-tree^{tree})
+	2:blob:rootfile:$(git rev-parse shared-tree:rootfile)
+	3:tree:aaa/:$(git rev-parse shared-tree:aaa)
+	4:tree:zzz/:$(git rev-parse shared-tree:zzz)
+	5:blob:zzz/file:$(git rev-parse shared-tree:zzz/file)
+	blobs:2
+	commits:1
+	tags:0
+	trees:3
+	EOF
+
+	test_cmp_sorted expect out
+'
+
 test_done