diff --git a/edalize/tools/modelsim.py b/edalize/tools/modelsim.py
new file mode 100644
index 000000000..612f6c5a3
--- /dev/null
+++ b/edalize/tools/modelsim.py
@@ -0,0 +1,220 @@
+# Copyright edalize contributors
+# Licensed under the 2-Clause BSD License, see LICENSE for details.
+# SPDX-License-Identifier: BSD-2-Clause
+
+import os
+import logging
+
+from edalize.tools.edatool import Edatool
+from edalize.utils import EdaCommands
+
+logger = logging.getLogger(__name__)
+
+
+class Modelsim(Edatool):
+    description = "ModelSim simulator from Mentor Graphics"
+
+    TOOL_OPTIONS = {
+        "compilation_mode": {
+            "type": "str",
+            "desc": "Common or separate compilation, sep - for separate compilation, common - for common compilation",
+        },
+        "vcom_options": {
+            "type": "str",
+            "desc": "Additional options for compilation with vcom",
+        },
+        "vlog_options": {
+            "type": "str",
+            "desc": "Additional options for compilation with vlog",
+        },
+        "vsim_options": {
+            "type": "str",
+            "desc": "Additional run options for vsim",
+        },
+        # run_options?
+    }
+
+    def _write_build_rtl_tcl_file(self, tcl_main):
+        incdirs = []
+        libs = []
+        vlog_files = []
+
+        tcl_build_rtl = open(os.path.join(self.work_root, "edalize_build_rtl.tcl"), "w")
+
+        # Fill up incdirs with all include directories, before looping through all files.
+        for f in self.files:
+            self._add_include_dir(f, incdirs)
+
+        vlog_include_dirs = ["+incdir+" + d.replace("\\", "/") for d in incdirs]
+
+        common_compilation = self.tool_options.get("compilation_mode") == "common"
+
+        for f in self.files:
+            if not f.get("logical_name"):
+                f["logical_name"] = "work"
+            if not f["logical_name"] in libs:
+                tcl_build_rtl.write("vlib {}\n".format(f["logical_name"]))
+                libs.append(f["logical_name"])
+            if f["file_type"].startswith("verilogSource") or f["file_type"].startswith(
+                "systemVerilogSource"
+            ):
+                cmd = None
+
+                if not f.get("is_include_file"):
+                    # Add vlog command for non-include file types
+                    vlog_files.append(f["name"])
+                    cmd = "vlog"
+
+                args = []
+
+                args += self.tool_options.get("vlog_options", [])
+
+                for k, v in self.vlogdefine.items():
+                    args += ["+define+{}={}".format(k, self._param_value_str(v))]
+
+                if f["file_type"].startswith("systemVerilogSource"):
+                    args += ["-sv"]
+
+                args += vlog_include_dirs
+            elif f["file_type"].startswith("vhdlSource"):
+                cmd = "vcom"
+                if f["file_type"].endswith("-87"):
+                    args = ["-87"]
+                if f["file_type"].endswith("-93"):
+                    args = ["-93"]
+                if f["file_type"].endswith("-2008"):
+                    args = ["-2008"]
+                else:
+                    args = []
+
+                args += self.tool_options.get("vcom_options", [])
+
+            elif f["file_type"] == "tclSource":
+                cmd = None
+                tcl_main.write("do {}\n".format(f["name"]))
+            elif f["file_type"] == "user":
+                cmd = None
+            else:
+                _s = "{} has unknown file type '{}'"
+                logger.warning(_s.format(f["name"], f["file_type"]))
+                cmd = None
+            if cmd and ((cmd != "vlog") or not common_compilation):
+                args += ["-quiet"]
+                args += ["-work", f["logical_name"]]
+                args += [f["name"].replace("\\", "/")]
+                tcl_build_rtl.write("{} {}\n".format(cmd, " ".join(args)))
+        if common_compilation:
+            args = self.tool_options.get("vlog_options", [])
+            for k, v in self.vlogdefine.items():
+                args += ["+define+{}={}".format(k, self._param_value_str(v))]
+
+            _vlog_files = []
+            has_sv = False
+            for f in vlog_files:
+                _vlog_files.append(f["name"].replace("\\", "/"))
+                if f["file_type"].startswith("systemVerilogSource"):
+                    has_sv = True
+
+            if has_sv:
+                args += ["-sv"]
+            args += vlog_include_dirs
+            args += ["-quiet"]
+            args += ["-work", "work"]
+            args += ["-mfcu"]
+            tcl_build_rtl.write(f"vlog {' '.join(args)} {' '.join(_vlog_files)}")
+
+    def write_config_files(self):
+        """
+        Generate ModelSim specific makefile & TCL build files from template.
+        """
+
+        tcl_main = open(os.path.join(self.work_root, "edalize_main.tcl"), "w")
+        tcl_main.write("onerror { quit -code 1; }\n")
+        tcl_main.write("do edalize_build_rtl.tcl\n")
+        self._write_build_rtl_tcl_file(tcl_main)
+        tcl_main.close()
+
+        self.render_template(
+            "modelsim-makefile.j2",
+            "modelsim-makefile",
+            self.template_vars,
+        )
+
+    def setup(self, edam):
+        super().setup(edam)
+
+        depfiles = []
+
+        _parameters = []
+        for key, value in self.vlogparam.items():
+            _parameters += ["{}={}".format(key, self._param_value_str(value))]
+        for key, value in self.generic.items():
+            _parameters += [
+                "{}={}".format(key, self._param_value_str(value, bool_is_str=True))
+            ]
+        _plusargs = []
+        for key, value in self.plusarg.items():
+            _plusargs += ["{}={}".format(key, self._param_value_str(value))]
+
+        _vsim_options = self.tool_options.get("vsim_options", [])
+        _modules = [m["name"] for m in self.vpi_modules]
+        _clean_targets = " ".join(["clean_" + m for m in _modules])
+
+        self.template_vars = {
+            "toplevel": self.toplevel,
+            "name": self.name,
+            "vsim_options": " ".join(_vsim_options),
+            "parameters": " ".join(_parameters),
+            "plusargs": " ".join(_plusargs),
+            "modules": " ".join(_modules),
+        }
+
+        commands = EdaCommands()
+
+        commands.add(
+            ["make"]
+            + [
+                "-f",
+                "modelsim-makefile",
+                "work",
+            ],
+            ["modelsim-build"],
+            depfiles,
+        )
+
+        commands.add(
+            ["make"]
+            + [
+                "-f",
+                "modelsim-makefile",
+                "run",
+            ],
+            ["modelsim-run"],
+            ["modelsim-build"],
+        )
+
+        commands.add(
+            ["make"]
+            + [
+                "-f",
+                "modelsim-makefile",
+                "run-gui",
+            ],
+            ["modelsim-run-gui"],
+            ["modelsim-build"],
+        )
+
+        commands.set_default_target("modelsim-build")
+        self.commands = commands
+
+    def run(self):
+        args = ["modelsim-run"]
+
+        # Set plusargs
+        if self.plusarg:
+            plusargs = []
+            for key, value in self.plusarg.items():
+                plusargs += ["{}={}".format(key, self._param_value_str(value))]
+            args.append("PLUSARGS=" + " ".join(plusargs))
+
+        return ("make", args, self.work_root)
diff --git a/edalize/tools/templates/modelsim/modelsim-makefile.j2 b/edalize/tools/templates/modelsim/modelsim-makefile.j2
new file mode 100644
index 000000000..3aef76a45
--- /dev/null
+++ b/edalize/tools/templates/modelsim/modelsim-makefile.j2
@@ -0,0 +1,44 @@
+#Generated by Edalize
+ifndef MODEL_TECH
+$(error Environment variable MODEL_TECH was not found. It should be set to <modelsim install path>/bin)
+endif
+
+CC ?= gcc
+CFLAGS   := -fPIC -fno-stack-protector -g -std=c99
+CXXFLAGS := -fPIC -fno-stack-protector -g
+
+LD ?= ld
+LDFLAGS := -shared -E
+
+#Try to determine if ModelSim is 32- or 64-bit.
+#To manually override, set the environment MTI_VCO_MODE to 32 or 64
+ifeq ($(findstring 64, $(shell $(MODEL_TECH)/../vco)),)
+CFLAGS   += -m32
+CXXFLAGS += -m32
+LDFLAGS  += -melf_i386
+endif
+
+RM ?= rm
+INCS := -I$(MODEL_TECH)/../include
+
+VSIM ?= $(MODEL_TECH)/vsim
+
+TOPLEVEL      := {{ toplevel }}
+VPI_MODULES   := {{ modules }}
+PARAMETERS    ?= {{ parameters }}
+PLUSARGS      ?= {{ plusargs }}
+VSIM_OPTIONS  ?= {{ vsim_options }}
+EXTRA_OPTIONS ?= $(VSIM_OPTIONS) $(addprefix -g,$(PARAMETERS)) $(addprefix +,$(PLUSARGS))
+
+all: work $(VPI_MODULES)
+
+run: work $(VPI_MODULES)
+	$(VSIM) -c $(addprefix -pli ,$(VPI_MODULES)) $(EXTRA_OPTIONS) -do "run -all; quit -code [expr [coverage attribute -name TESTSTATUS -concise] >= 2 ? [coverage attribute -name TESTSTATUS -concise] : 0]; exit" $(TOPLEVEL)
+
+run-gui: work $(VPI_MODULES)
+	$(VSIM) -gui $(addprefix -pli ,$(VPI_MODULES)) $(EXTRA_OPTIONS) $(TOPLEVEL)
+
+work:
+	$(VSIM) -c -do "do edalize_main.tcl; exit"
+
+clean: {{ clean_targets }}
\ No newline at end of file
diff --git a/tests/flows/sim/modelsim/Makefile b/tests/flows/sim/modelsim/Makefile
new file mode 100644
index 000000000..a5955519c
--- /dev/null
+++ b/tests/flows/sim/modelsim/Makefile
@@ -0,0 +1,22 @@
+#Auto generated by Edalize
+
+all: post_build
+
+pre_build: 
+
+modelsim-build: | pre_build
+	$(EDALIZE_LAUNCHER) make -f modelsim-makefile work
+
+modelsim-run: modelsim-build
+	$(EDALIZE_LAUNCHER) make -f modelsim-makefile run
+
+modelsim-run-gui: modelsim-build
+	$(EDALIZE_LAUNCHER) make -f modelsim-makefile run-gui
+
+post_build: modelsim-build
+
+pre_run: 
+
+run: pre_run
+
+post_run: run
diff --git a/tests/flows/sim/modelsim/edalize_build_rtl.tcl b/tests/flows/sim/modelsim/edalize_build_rtl.tcl
new file mode 100644
index 000000000..36640eb11
--- /dev/null
+++ b/tests/flows/sim/modelsim/edalize_build_rtl.tcl
@@ -0,0 +1,9 @@
+vlib work
+vlog +define+vlogdefine_bool=1 +define+vlogdefine_int=42 +define+vlogdefine_str=hello -sv +incdir+. -quiet -work work sv_file.sv
+vlog +define+vlogdefine_bool=1 +define+vlogdefine_int=42 +define+vlogdefine_str=hello +incdir+. -quiet -work work vlog_file.v
+vlog +define+vlogdefine_bool=1 +define+vlogdefine_int=42 +define+vlogdefine_str=hello +incdir+. -quiet -work work vlog05_file.v
+vcom -quiet -work work vhdl_file.vhd
+vlib libx
+vcom -quiet -work libx vhdl_lfile
+vcom -2008 -quiet -work work vhdl2008_file
+vlog +define+vlogdefine_bool=1 +define+vlogdefine_int=42 +define+vlogdefine_str=hello -sv +incdir+. -quiet -work work another_sv_file.sv
diff --git a/tests/flows/sim/modelsim/edalize_main.tcl b/tests/flows/sim/modelsim/edalize_main.tcl
new file mode 100644
index 000000000..ec4861eb3
--- /dev/null
+++ b/tests/flows/sim/modelsim/edalize_main.tcl
@@ -0,0 +1,3 @@
+onerror { quit -code 1; }
+do edalize_build_rtl.tcl
+do tcl_file.tcl
diff --git a/tests/flows/sim/modelsim/modelsim-makefile b/tests/flows/sim/modelsim/modelsim-makefile
new file mode 100644
index 000000000..4a6f60362
--- /dev/null
+++ b/tests/flows/sim/modelsim/modelsim-makefile
@@ -0,0 +1,44 @@
+#Generated by Edalize
+ifndef MODEL_TECH
+$(error Environment variable MODEL_TECH was not found. It should be set to <modelsim install path>/bin)
+endif
+
+CC ?= gcc
+CFLAGS   := -fPIC -fno-stack-protector -g -std=c99
+CXXFLAGS := -fPIC -fno-stack-protector -g
+
+LD ?= ld
+LDFLAGS := -shared -E
+
+#Try to determine if ModelSim is 32- or 64-bit.
+#To manually override, set the environment MTI_VCO_MODE to 32 or 64
+ifeq ($(findstring 64, $(shell $(MODEL_TECH)/../vco)),)
+CFLAGS   += -m32
+CXXFLAGS += -m32
+LDFLAGS  += -melf_i386
+endif
+
+RM ?= rm
+INCS := -I$(MODEL_TECH)/../include
+
+VSIM ?= $(MODEL_TECH)/vsim
+
+TOPLEVEL      := top_module
+VPI_MODULES   := 
+PARAMETERS    ?= vlogparam_bool=1 vlogparam_int=42 vlogparam_str=hello
+PLUSARGS      ?= plusarg_bool=1 plusarg_int=42 plusarg_str=hello
+VSIM_OPTIONS  ?= 
+EXTRA_OPTIONS ?= $(VSIM_OPTIONS) $(addprefix -g,$(PARAMETERS)) $(addprefix +,$(PLUSARGS))
+
+all: work $(VPI_MODULES)
+
+run: work $(VPI_MODULES)
+	$(VSIM) -c $(addprefix -pli ,$(VPI_MODULES)) $(EXTRA_OPTIONS) -do "run -all; quit -code [expr [coverage attribute -name TESTSTATUS -concise] >= 2 ? [coverage attribute -name TESTSTATUS -concise] : 0]; exit" $(TOPLEVEL)
+
+run-gui: work $(VPI_MODULES)
+	$(VSIM) -gui $(addprefix -pli ,$(VPI_MODULES)) $(EXTRA_OPTIONS) $(TOPLEVEL)
+
+work:
+	$(VSIM) -c -do "do edalize_main.tcl; exit"
+
+clean: 
\ No newline at end of file
diff --git a/tests/test_flow_sim.py b/tests/test_flow_sim.py
new file mode 100644
index 000000000..532a6593c
--- /dev/null
+++ b/tests/test_flow_sim.py
@@ -0,0 +1,17 @@
+import filecmp
+import os
+from .edalize_flow_common import flow_fixture
+from .edalize_common import tests_dir
+
+
+def test_flow_sim_modelsim(flow_fixture):
+    flow_options = {
+        "tool": "modelsim",
+    }
+
+    ff = flow_fixture("sim", flow_options=flow_options, ref_subdir="modelsim")
+
+    ff.compare_makefile()
+    ff.compare_config_files(
+        ["edalize_build_rtl.tcl", "edalize_main.tcl", "modelsim-makefile"]
+    )