diff --git a/object_store/src/memory.rs b/object_store/src/memory.rs
index 41cfcc490da6..41ee1091a3b2 100644
--- a/object_store/src/memory.rs
+++ b/object_store/src/memory.rs
@@ -16,6 +16,7 @@
 // under the License.
 
 //! An in-memory object store implementation
+use crate::multipart::{MultiPartStore, PartId};
 use crate::util::InvalidGetRange;
 use crate::{
     path::Path, GetRange, GetResult, GetResultPayload, ListResult, ObjectMeta, ObjectStore,
@@ -28,8 +29,8 @@ use chrono::{DateTime, Utc};
 use futures::{stream::BoxStream, StreamExt};
 use parking_lot::RwLock;
 use snafu::{OptionExt, ResultExt, Snafu};
-use std::collections::BTreeMap;
 use std::collections::BTreeSet;
+use std::collections::{BTreeMap, HashMap};
 use std::io;
 use std::ops::Range;
 use std::pin::Pin;
@@ -52,6 +53,12 @@ enum Error {
 
     #[snafu(display("ETag required for conditional update"))]
     MissingETag,
+
+    #[snafu(display("MultipartUpload not found: {id}"))]
+    UploadNotFound { id: String },
+
+    #[snafu(display("Missing part at index: {part}"))]
+    MissingPart { part: usize },
 }
 
 impl From<Error> for super::Error {
@@ -101,6 +108,12 @@ impl Entry {
 struct Storage {
     next_etag: usize,
     map: BTreeMap<Path, Entry>,
+    uploads: HashMap<usize, PartStorage>,
+}
+
+#[derive(Debug, Default, Clone)]
+struct PartStorage {
+    parts: Vec<Option<Bytes>>,
 }
 
 type SharedStorage = Arc<RwLock<Storage>>;
@@ -154,6 +167,24 @@ impl Storage {
             }
         }
     }
+
+    fn upload_mut(&mut self, id: &MultipartId) -> Result<&mut PartStorage> {
+        let parts = id
+            .parse()
+            .ok()
+            .and_then(|x| self.uploads.get_mut(&x))
+            .context(UploadNotFoundSnafu { id })?;
+        Ok(parts)
+    }
+
+    fn remove_upload(&mut self, id: &MultipartId) -> Result<PartStorage> {
+        let parts = id
+            .parse()
+            .ok()
+            .and_then(|x| self.uploads.remove(&x))
+            .context(UploadNotFoundSnafu { id })?;
+        Ok(parts)
+    }
 }
 
 impl std::fmt::Display for InMemory {
@@ -359,6 +390,64 @@ impl ObjectStore for InMemory {
     }
 }
 
+#[async_trait]
+impl MultiPartStore for InMemory {
+    async fn create_multipart(&self, _path: &Path) -> Result<MultipartId> {
+        let mut storage = self.storage.write();
+        let etag = storage.next_etag;
+        storage.next_etag += 1;
+        storage.uploads.insert(etag, Default::default());
+        Ok(etag.to_string())
+    }
+
+    async fn put_part(
+        &self,
+        _path: &Path,
+        id: &MultipartId,
+        part_idx: usize,
+        data: Bytes,
+    ) -> Result<PartId> {
+        let mut storage = self.storage.write();
+        let upload = storage.upload_mut(id)?;
+        if part_idx <= upload.parts.len() {
+            upload.parts.resize(part_idx + 1, None);
+        }
+        upload.parts[part_idx] = Some(data);
+        Ok(PartId {
+            content_id: Default::default(),
+        })
+    }
+
+    async fn complete_multipart(
+        &self,
+        path: &Path,
+        id: &MultipartId,
+        _parts: Vec<PartId>,
+    ) -> Result<PutResult> {
+        let mut storage = self.storage.write();
+        let upload = storage.remove_upload(id)?;
+
+        let mut cap = 0;
+        for (part, x) in upload.parts.iter().enumerate() {
+            cap += x.as_ref().context(MissingPartSnafu { part })?.len();
+        }
+        let mut buf = Vec::with_capacity(cap);
+        for x in &upload.parts {
+            buf.extend_from_slice(x.as_ref().unwrap())
+        }
+        let etag = storage.insert(path, buf.into());
+        Ok(PutResult {
+            e_tag: Some(etag.to_string()),
+            version: None,
+        })
+    }
+
+    async fn abort_multipart(&self, _path: &Path, id: &MultipartId) -> Result<()> {
+        self.storage.write().remove_upload(id)?;
+        Ok(())
+    }
+}
+
 impl InMemory {
     /// Create new in-memory storage.
     pub fn new() -> Self {
@@ -444,6 +533,7 @@ mod tests {
         copy_if_not_exists(&integration).await;
         stream_get(&integration).await;
         put_opts(&integration, true).await;
+        multipart(&integration, &integration).await;
     }
 
     #[tokio::test]