diff --git a/.gitmodules b/.gitmodules
index 4f21369e..3aacc69d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -148,3 +148,6 @@
 [submodule "generators/rocket-chip-inclusive-cache"]
 	path = generators/rocket-chip-inclusive-cache
 	url = https://github.com/chipsalliance/rocket-chip-inclusive-cache.git
+[submodule "tools/circt"]
+	path = tools/circt
+	url = https://github.com/llvm/circt.git
diff --git a/scripts/build-circt-from-source.sh b/scripts/build-circt-from-source.sh
new file mode 100755
index 00000000..5477534d
--- /dev/null
+++ b/scripts/build-circt-from-source.sh
@@ -0,0 +1,102 @@
+#!/usr/bin/env bash
+
+# exit script if any command fails
+set -e
+set -o pipefail
+
+RDIR=$(git rev-parse --show-toplevel)
+
+# get helpful utilities
+source $RDIR/scripts/utils.sh
+
+common_setup
+
+# Allow user to override MAKE
+[ -n "${MAKE:+x}" ] || MAKE=$(command -v gnumake || command -v gmake || command -v make)
+readonly MAKE
+
+usage() {
+    echo "usage: ${0}"
+    echo ""
+    echo "Options"
+    echo "   --prefix -p PREFIX    : Install destination."
+    echo "   --help -h             : Display this message"
+    exit "$1"
+}
+
+PREFIX=""
+
+# getopts does not support long options, and is inflexible
+while [ "$1" != "" ];
+do
+    case $1 in
+        -h | -H | --help | help )
+            usage 3 ;;
+        -p | --prefix )
+            shift
+            PREFIX=$(realpath $1) ;;
+        * )
+            error "invalid option $1"
+            usage 1 ;;
+    esac
+    shift
+done
+
+if [ -z "$PREFIX" ] ; then
+    error "ERROR: Prefix not given."
+    exit 1
+fi
+
+
+
+echo "Cloning CIRCT"
+(
+    cd $RDIR/tools
+    git submodule update --init --progress circt
+)
+echo "Cloning CIRCT/LLVM"
+(
+    cd $RDIR/tools/circt
+    git submodule init
+    # The settings in circt/.gitmodules don't "stick", so force-set them here
+    git config submodule.llvm.shallow true
+    git config submodule.llvm.branch main
+    git submodule update --recommend-shallow --progress llvm
+)
+
+echo "Building CIRCT's LLVM/MLIR"
+(
+    cd $RDIR/tools/circt
+    rm -rf llvm/build
+    mkdir llvm/build
+    cd llvm/build
+    cmake -G Ninja ../llvm \
+	  -DLLVM_ENABLE_PROJECTS="mlir" \
+	  -DLLVM_TARGETS_TO_BUILD="host" \
+	  -DLLVM_ENABLE_ASSERTIONS=ON \
+	  -DCMAKE_BUILD_TYPE=RELEASE \
+	  -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+    ninja
+)
+
+echo "Building CIRCT"
+(
+    cd $RDIR/tools/circt
+    rm -rf build
+    mkdir build
+    cd build
+    cmake -G Ninja .. \
+	  -DMLIR_DIR=../llvm/build/lib/cmake/mlir \
+	  -DLLVM_DIR=../llvm/build/lib/cmake/llvm \
+	  -DLLVM_ENABLE_ASSERTIONS=ON \
+	  -DCMAKE_BUILD_TYPE=RELEASE \
+	  -DCMAKE_INSTALL_PREFIX=$PREFIX
+    ninja
+)
+
+echo "Installing CIRCT to $PREFIX"
+(
+    cd $RDIR/tools/circt/build
+    ninja install
+)
+
diff --git a/scripts/build-setup.sh b/scripts/build-setup.sh
index d8a08c1c..56f56506 100755
--- a/scripts/build-setup.sh
+++ b/scripts/build-setup.sh
@@ -39,6 +39,7 @@ usage() {
     echo "  --verbose -v            : Verbose printout"
     echo "  --use-unpinned-deps -ud : Use unpinned conda environment"
     echo "  --use-lean-conda        : Install a leaner version of the repository (Smaller conda env, no FireSim, no FireMarshal)"
+    echo "  --build-circt           : Builds CIRCT from source, instead of downloading the precompiled binary"
 
     echo "  --skip -s N             : Skip step N in the list above. Use multiple times to skip multiple steps ('-s N -s M ...')."
     echo "  --skip-conda            : Skip Conda initialization (step 1)"
@@ -60,6 +61,7 @@ VERBOSE_FLAG=""
 USE_UNPINNED_DEPS=false
 USE_LEAN_CONDA=false
 SKIP_LIST=()
+BUILD_CIRCT=false
 
 # getopts does not support long options, and is inflexible
 while [ "$1" != "" ];
@@ -75,6 +77,8 @@ do
         --use-lean-conda)
             USE_LEAN_CONDA=true
             SKIP_LIST+=(4 6 7 8 9) ;;
+        --build-circt)
+            BUILD_CIRCT=true ;;
         -ud | --use-unpinned-deps )
             USE_UNPINNED_DEPS=true ;;
         --skip | -s)
@@ -306,13 +310,20 @@ if run_step "10"; then
         PREFIX=$RISCV
     fi
 
-    git submodule update --init $CYDIR/tools/install-circt &&
-    $CYDIR/tools/install-circt/bin/download-release-or-nightly-circt.sh \
-        -f circt-full-static-linux-x64.tar.gz \
-        -i $PREFIX \
-        -v version-file \
-        -x $CYDIR/conda-reqs/circt.json \
-        -g null
+    if [ "$BUILD_CIRCT" = true ] ; then
+	echo "Building CIRCT from source, and installing to $PREFIX"
+	$CYDIR/scripts/build-circt-from-source.sh --prefix $PREFIX
+    else
+	echo "Downloading CIRCT from nightly build"
+
+	git submodule update --init $CYDIR/tools/install-circt &&
+	    $CYDIR/tools/install-circt/bin/download-release-or-nightly-circt.sh \
+		-f circt-full-static-linux-x64.tar.gz \
+		-i $PREFIX \
+		-v version-file \
+		-x $CYDIR/conda-reqs/circt.json \
+		-g null
+    fi
     exit_if_last_command_failed
 fi
 
diff --git a/scripts/init-submodules-no-riscv-tools-nolog.sh b/scripts/init-submodules-no-riscv-tools-nolog.sh
index 1779b8d8..e46af0ca 100755
--- a/scripts/init-submodules-no-riscv-tools-nolog.sh
+++ b/scripts/init-submodules-no-riscv-tools-nolog.sh
@@ -82,6 +82,7 @@ cd "$RDIR"
             software/spec2017 \
             tools/dsptools \
             tools/rocket-dsp-utils \
+            tools/circt \
             vlsi/hammer-mentor-plugins
         do
             "$1" "${name%/}"
diff --git a/tools/circt b/tools/circt
new file mode 160000
index 00000000..9e0c1696
--- /dev/null
+++ b/tools/circt
@@ -0,0 +1 @@
+Subproject commit 9e0c1696f3caef4059c65774ad6b8efee91d9d9e