diff --git a/projects/h3/Dockerfile b/projects/h3/Dockerfile
new file mode 100644
index 000000000..98f6e6ca4
--- /dev/null
+++ b/projects/h3/Dockerfile
@@ -0,0 +1,22 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+
+FROM gcr.io/oss-fuzz-base/base-builder
+RUN apt-get update && apt-get install -y make autoconf automake libtool \
+  pkg-config
+RUN git clone --depth 1 https://github.com/uber/h3
+WORKDIR h3
+COPY build.sh h3_fuzzer.c $SRC/
diff --git a/projects/h3/build.sh b/projects/h3/build.sh
new file mode 100755
index 000000000..bc35a2db8
--- /dev/null
+++ b/projects/h3/build.sh
@@ -0,0 +1,34 @@
+#!/bin/bash -eu
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+
+mkdir build
+cd build
+cmake ..
+make -j$(nproc)
+
+$CC $CFLAGS -DH3_PREFIX="" \
+    -I/src/h3/src/apps/applib/include \
+    -I/src/h3/src/h3lib/include \
+    -I/src/h3/build/src/h3lib/include \
+    -o h3_fuzzer.o \
+    -c $SRC/h3_fuzzer.c
+
+$CC $CFLAGS $LIB_FUZZING_ENGINE -rdynamic \
+    h3_fuzzer.o \
+    -o $OUT/h3_fuzzer \
+    lib/libh3.a
+
diff --git a/projects/h3/h3_fuzzer.c b/projects/h3/h3_fuzzer.c
new file mode 100644
index 000000000..e0923e26a
--- /dev/null
+++ b/projects/h3/h3_fuzzer.c
@@ -0,0 +1,75 @@
+/*
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+*/
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "h3api.h"
+#include "utility.h"
+
+static const Direction DIGITS[7] = {CENTER_DIGIT,  K_AXES_DIGIT, J_AXES_DIGIT,
+                                    JK_AXES_DIGIT, I_AXES_DIGIT, IK_AXES_DIGIT,
+                                    IJ_AXES_DIGIT};
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  char *new_str = (char *)malloc(size + 1);
+  if (new_str == NULL) {
+    return 0;
+  }
+  memcpy(new_str, data, size);
+  new_str[size] = '\0';
+
+  H3Index h3;
+  h3 = H3_EXPORT(stringToH3)(new_str);
+
+  H3Index input[] = {h3, h3};
+  int inputSize = sizeof(input) / sizeof(H3Index);
+
+  // fuzz compactCells
+  H3Index *compacted = calloc(inputSize, sizeof(H3Index));
+  int err = compactCells(input, compacted, inputSize);
+
+  // fuzz uncompactCells
+  int compactedCount = 0;
+  for (int i = 0; i < inputSize; i++) {
+    if (compacted[i] != 0) {
+      compactedCount++;
+    }
+  }
+  if (compactedCount < 2) {
+    int uncompactRes = 10;
+    int64_t uncompactedSize =
+        uncompactCellsSize(compacted, inputSize, uncompactRes);
+
+    H3Index *uncompacted = calloc(uncompactedSize, sizeof(H3Index));
+    int err2 = uncompactCells(compacted, compactedCount, uncompacted,
+                              uncompactedSize, uncompactRes);
+    free(uncompacted);
+  }
+
+  // fuzz h3NeighborRotations
+  int rotations = 0;
+  for (int i = 0; i < 7; i++) {
+    h3NeighborRotations(h3, DIGITS[i], &rotations);
+  }
+  free(compacted);
+  free(new_str);
+  return 0;
+}
diff --git a/projects/h3/project.yaml b/projects/h3/project.yaml
new file mode 100644
index 000000000..c56084a7c
--- /dev/null
+++ b/projects/h3/project.yaml
@@ -0,0 +1,11 @@
+homepage: "https://github.com/uber/h3"
+language: c
+primary_contact: "isaac@isaacbrodsky.com"
+auto_ccs:
+  - "Adam@adalogics.com"
+  - "h3-dev@googlegroups.com"
+sanitizers:
+  - address
+  - undefined
+  - memory
+main_repo: 'https://github.com/uber/h3'