diff --git a/configforge/commands/convert.py b/configforge/commands/convert.py
new file mode 100644
index 0000000..7a3f4d1
--- /dev/null
+++ b/configforge/commands/convert.py
@@ -0,0 +1,120 @@
+"""Convert command for ConfigForge."""
+
+import os
+from pathlib import Path
+from typing import Optional
+
+import click
+
+from configforge.exceptions import (
+    ConversionError,
+    FileOperationError,
+    InvalidConfigFormatError,
+)
+from configforge.formatters import JSONHandler, YAMLHandler, TOMLHandler, ENVHandler
+from configforge.utils.file_parser import detect_format
+
+
+OUTPUT_FORMAT_MAP = {
+    "json": ("json", JSONHandler),
+    "yaml": ("yaml", YAMLHandler),
+    "toml": ("toml", TOMLHandler),
+    "env": ("env", ENVHandler),
+}
+
+
+@click.command("convert")
+@click.argument("input_file", type=click.Path(exists=True))
+@click.option(
+    "--output",
+    "-o",
+    type=click.Path(),
+    help="Output file path (default: stdout)",
+)
+@click.option(
+    "--format",
+    "-f",
+    type=click.Choice(["json", "yaml", "toml", "env"]),
+    help="Output format (default: auto-detect from extension)",
+)
+@click.option(
+    "--indent",
+    is_flag=True,
+    default=False,
+    help="Use indented output for JSON",
+)
+def convert(
+    input_file: str,
+    output: Optional[str],
+    format: Optional[str],
+    indent: bool,
+) -> None:
+    """Convert a configuration file between formats."""
+    try:
+        input_format = detect_format(input_file)
+
+        if format:
+            output_format = format
+        elif output:
+            output_format = detect_format(output)
+        else:
+            raise ConversionError(
+                "Output format must be specified via --format or output file extension"
+            )
+
+        data = _read_input(input_file, input_format)
+        content = _format_output(data, output_format, indent)
+
+        if output:
+            _write_output(output, content)
+            click.echo(f"Converted {input_file} ({input_format}) -> {output} ({output_format})")
+        else:
+            click.echo(content)
+
+    except (InvalidConfigFormatError, FileOperationError, ConversionError) as e:
+        click.echo(f"Error: {e.message}", err=True)
+        click.get_current_context().exit(1)
+
+
+def _read_input(filepath: str, format_type: str) -> dict:
+    """Read and parse input file."""
+    handlers = {
+        "json": JSONHandler,
+        "yaml": YAMLHandler,
+        "toml": TOMLHandler,
+        "env": ENVHandler,
+    }
+
+    handler = handlers.get(format_type)
+    if not handler:
+        raise InvalidConfigFormatError(f"Unsupported format: {format_type}")
+
+    return handler.read(filepath)
+
+
+def _format_output(data: dict, format_type: str, indent: bool = False) -> str:
+    """Format data to output string."""
+    handlers = {
+        "json": lambda d: JSONHandler.dumps(d, indent=2 if indent else 0),
+        "yaml": lambda d: YAMLHandler.dumps(d),
+        "toml": lambda d: TOMLHandler.dumps(d),
+        "env": lambda d: ENVHandler.dumps(d),
+    }
+
+    handler = handlers.get(format_type)
+    if not handler:
+        raise InvalidConfigFormatError(f"Unsupported output format: {format_type}")
+
+    return handler(data)
+
+
+def _write_output(filepath: str, content: str) -> None:
+    """Write content to output file."""
+    try:
+        os.makedirs(os.path.dirname(filepath) if os.path.dirname(filepath) else ".", exist_ok=True)
+        with open(filepath, "w", encoding="utf-8") as f:
+            f.write(content)
+    except PermissionError:
+        raise FileOperationError(f"Permission denied: {filepath}", filepath=filepath)
+    except OSError as e:
+        raise FileOperationError(f"Failed to write {filepath}: {str(e)}", filepath=filepath)