diff --git a/Cargo.lock b/Cargo.lock
index 100f6188..600b48dd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3145,9 +3145,9 @@ checksum = "f87165f0995f63a9fbeea62b64d10b4d9d8e78ec6d7d51fb2125fda7bb36788f"
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.12"
+version = "0.103.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8279bb85272c9f10811ae6a6c547ff594d6a7f3c6c6b02ee9726d1d0dcfcdd06"
+checksum = "61c429a8649f110dddef65e2a5ad240f747e85f7758a6bccc7e5777bd33f756e"
 dependencies = [
  "aws-lc-rs",
  "ring",
diff --git a/Cargo.nix b/Cargo.nix
index db19601b..9abd0950 100644
--- a/Cargo.nix
+++ b/Cargo.nix
@@ -10491,9 +10491,9 @@ rec {
       };
       "rustls-webpki" = rec {
         crateName = "rustls-webpki";
-        version = "0.103.12";
+        version = "0.103.13";
         edition = "2021";
-        sha256 = "01nxzkfd1l96jzp04svc7iznlkarzx3wb9p63a0i17rc4y2vnyc2";
+        sha256 = "0vkm7z9pnxz5qz66p2kmyy2pwx0g4jnsbqk5xzfhs4czcjl2ki31";
         libName = "webpki";
         dependencies = [
           {
diff --git a/rust/stackable-cockpit/src/helm.rs b/rust/stackable-cockpit/src/helm.rs
index 76528584..baad9ee1 100644
--- a/rust/stackable-cockpit/src/helm.rs
+++ b/rust/stackable-cockpit/src/helm.rs
@@ -38,6 +38,40 @@ pub struct ChartRepo {
     pub url: String,
 }
 
+/// The kind of source a chart repo URL refers to.
+///
+/// [Self::Oci] and [Self::Local] don't need special handling, but [Self::Repo]
+/// needs to call `helm::add_repo`.
+///
+/// Note: We don't yet support local repositories, so an error should be emitted
+/// if the source is [Self::Local].
+#[derive(Debug, PartialEq)]
+pub enum ChartSourceKind {
+    /// OCI registry (url starts with `oci://`)
+    Oci,
+
+    /// Traditional index.yaml-based repository (url starts with `http://` or `https://`)
+    Repo,
+
+    /// Local filesystem path (not yet supported)
+    ///
+    /// This is the fallback if not oci or http(s).
+    Local,
+}
+
+impl ChartRepo {
+    /// Determine the kind of chart source based on the URL scheme.
+    pub fn source_kind(&self) -> ChartSourceKind {
+        if self.url.starts_with("oci://") {
+            ChartSourceKind::Oci
+        } else if self.url.starts_with("http://") || self.url.starts_with("https://") {
+            ChartSourceKind::Repo
+        } else {
+            ChartSourceKind::Local
+        }
+    }
+}
+
 #[derive(Debug, Snafu)]
 pub enum Error {
     #[snafu(display("failed to parse URL"))]
@@ -505,3 +539,27 @@ where
 
     serde_yaml::from_str(&index_file_content).context(DeserializeYamlSnafu)
 }
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+
+    #[rstest]
+    #[case("oci://oci.stackable.tech/sdp-charts", ChartSourceKind::Oci)]
+    #[case(
+        "https://repo.stackable.tech/repository/helm-stable",
+        ChartSourceKind::Repo
+    )]
+    #[case("http://example.com/charts", ChartSourceKind::Repo)]
+    #[case("./charts/my-chart", ChartSourceKind::Local)]
+    #[case("/absolute/path/to/chart", ChartSourceKind::Local)]
+    fn source_kind(#[case] url: &str, #[case] expected: ChartSourceKind) {
+        let repo = ChartRepo {
+            name: "test".to_owned(),
+            url: url.to_owned(),
+        };
+        assert_eq!(repo.source_kind(), expected);
+    }
+}
diff --git a/rust/stackable-cockpit/src/platform/manifests.rs b/rust/stackable-cockpit/src/platform/manifests.rs
index 6e5dd45d..36531ded 100644
--- a/rust/stackable-cockpit/src/platform/manifests.rs
+++ b/rust/stackable-cockpit/src/platform/manifests.rs
@@ -56,6 +56,10 @@ pub enum Error {
         source: helm::Error,
     },
 
+    /// This error indicates that the Helm chart source kind is not supported.
+    #[snafu(display("local Helm chart sources are not yet supported (source: {chart_source:?})"))]
+    UnsupportedChartSource { chart_source: String },
+
     /// This error indicates that Helm chart options could not be serialized
     /// into YAML.
     #[snafu(display("failed to serialize Helm chart options"))]
@@ -104,12 +108,23 @@ pub trait InstallManifestsExt {
 
                     info!(helm_chart.name, helm_chart.version, "Installing Helm chart",);
 
-                    // Assumption: that all manifest helm charts refer to repos not registries
-                    helm::add_repo(&helm_chart.repo.name, &helm_chart.repo.url).context(
-                        AddHelmRepositorySnafu {
-                            repo_name: helm_chart.repo.name.clone(),
-                        },
-                    )?;
+                    let chart_source = match helm_chart.repo.source_kind() {
+                        helm::ChartSourceKind::Repo => {
+                            helm::add_repo(&helm_chart.repo.name, &helm_chart.repo.url).context(
+                                AddHelmRepositorySnafu {
+                                    repo_name: helm_chart.repo.name.clone(),
+                                },
+                            )?;
+                            &helm_chart.repo.name
+                        }
+                        helm::ChartSourceKind::Oci => &helm_chart.repo.url,
+                        helm::ChartSourceKind::Local => {
+                            return UnsupportedChartSourceSnafu {
+                                chart_source: helm_chart.repo.url.clone(),
+                            }
+                            .fail();
+                        }
+                    };
 
                     // Serialize chart options to string
                     let values_yaml = serde_yaml::to_string(&helm_chart.options)
@@ -119,7 +134,7 @@ pub trait InstallManifestsExt {
                     helm::upgrade_or_install_release_from_repo_or_registry(
                         &helm_chart.release_name,
                         helm::ChartVersion {
-                            chart_source: &helm_chart.repo.name,
+                            chart_source,
                             chart_name: &helm_chart.name,
                             chart_version: Some(&helm_chart.version),
                         },
diff --git a/rust/stackablectl/CHANGELOG.md b/rust/stackablectl/CHANGELOG.md
index bc493c58..91507e68 100644
--- a/rust/stackablectl/CHANGELOG.md
+++ b/rust/stackablectl/CHANGELOG.md
@@ -10,9 +10,11 @@ All notable changes to this project will be documented in this file.
 - Add `uninstall` subcommand for `demo`/`stack` commands ([#429]).
 - Add confirmation prompt to `install` subcommand for namespace selection ([#429]).
 - Add `--assume-yes` option for running commands non-interactively ([#429]).
+- Support Helm charts sourced from OCI registries in demo/stack manifests ([#440]).
 
 [#429]: https://github.com/stackabletech/stackable-cockpit/pull/429
 [#438]: https://github.com/stackabletech/stackable-cockpit/pull/438
+[#440]: https://github.com/stackabletech/stackable-cockpit/pull/440
 
 ## [1.4.0] - 2026-03-18