diff --git a/vibeguard/reports/generator.py b/vibeguard/reports/generator.py
new file mode 100644
index 0000000..4a12225
--- /dev/null
+++ b/vibeguard/reports/generator.py
@@ -0,0 +1,174 @@
+"""Report generator for VibeGuard."""
+
+import json
+from datetime import datetime
+from pathlib import Path
+from typing import Any
+
+from jinja2 import Environment, FileSystemLoader
+
+
+class ReportGenerator:
+    """Generates reports in various formats."""
+
+    def __init__(self, template_dir: str | None = None) -> None:
+        """Initialize report generator with templates."""
+        self.template_dir = template_dir or str(
+            Path(__file__).parent.parent / "templates"
+        )
+        self._env = Environment(
+            loader=FileSystemLoader(self.template_dir),
+            autoescape=True,
+        )
+
+    def generate_json(
+        self, issues: list[dict[str, Any]], output_path: str
+    ) -> None:
+        """Generate JSON report."""
+        report = {
+            "version": "0.1.0",
+            "timestamp": datetime.utcnow().isoformat(),
+            "summary": self._generate_summary(issues),
+            "issues": issues,
+        }
+
+        with open(output_path, "w", encoding="utf-8") as f:
+            json.dump(report, f, indent=2)
+
+    def load_json(self, input_path: str) -> list[dict[str, Any]]:
+        """Load issues from JSON file."""
+        with open(input_path, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        return data.get("issues", [])
+
+    def generate_html(
+        self,
+        issues: list[dict[str, Any]],
+        output_path: str,
+        summary: dict[str, int] | None = None,
+    ) -> None:
+        """Generate HTML report."""
+        if summary is None:
+            summary = self._generate_summary(issues)
+
+        template = self._env.get_template("report.html")
+        html_content = template.render(
+            title="VibeGuard Analysis Report",
+            timestamp=datetime.utcnow().isoformat(),
+            summary=summary,
+            issues=issues,
+            total_issues=len(issues),
+        )
+
+        with open(output_path, "w", encoding="utf-8") as f:
+            f.write(html_content)
+
+    def generate_sarif(
+        self, issues: list[dict[str, Any]], output_path: str
+    ) -> None:
+        """Generate SARIF report for GitHub Code Scanning."""
+        sarif = {
+            "$schema": "https://raw.githubusercontent.com/oasis-tcs/sarif-spec/master/Schemata/sarif-schema-2.1.0.json",
+            "version": "2.1.0",
+            "runs": [
+                {
+                    "tool": {
+                        "driver": {
+                            "name": "VibeGuard",
+                            "version": "0.1.0",
+                            "informationUri": "https://github.com/vibeguard/vibeguard",
+                            "rules": self._generate_sarif_rules(issues),
+                        }
+                    },
+                    "results": self._generate_sarif_results(issues),
+                }
+            ],
+        }
+
+        with open(output_path, "w", encoding="utf-8") as f:
+            json.dump(sarif, f, indent=2)
+
+    def _generate_summary(self, issues: list[dict[str, Any]]) -> dict[str, int]:
+        """Generate summary statistics."""
+        summary: dict[str, int] = {
+            "critical": 0,
+            "error": 0,
+            "warning": 0,
+            "info": 0,
+            "total": len(issues),
+        }
+
+        for issue in issues:
+            severity = issue.get("severity", "info")
+            summary[severity] = summary.get(severity, 0) + 1
+
+        return summary
+
+    def _generate_sarif_rules(
+        self, issues: list[dict[str, Any]]
+    ) -> list[dict[str, Any]]:
+        """Generate SARIF rule definitions."""
+        rules: dict[str, dict[str, Any]] = {}
+
+        for issue in issues:
+            rule_id = issue.get("pattern", "UNKNOWN")
+            if rule_id not in rules:
+                rules[rule_id] = {
+                    "id": rule_id,
+                    "name": rule_id,
+                    "shortDescription": {
+                        "text": issue.get("message", "Unknown issue")
+                    },
+                    "fullDescription": {
+                        "text": issue.get("suggestion", "")
+                    },
+                    "defaultConfiguration": {
+                        "level": self._severity_to_sarif_level(
+                            issue.get("severity", "warning")
+                        )
+                    },
+                }
+
+        return list(rules.values())
+
+    def _generate_sarif_results(
+        self, issues: list[dict[str, Any]]
+    ) -> list[dict[str, Any]]:
+        """Generate SARIF result objects."""
+        results: list[dict[str, Any]] = []
+
+        for issue in issues:
+            result = {
+                "ruleId": issue.get("pattern", "UNKNOWN"),
+                "message": {
+                    "text": issue.get("message", "")
+                },
+                "level": self._severity_to_sarif_level(
+                    issue.get("severity", "warning")
+                ),
+                "locations": [
+                    {
+                        "physicalLocation": {
+                            "artifactLocation": {
+                                "uri": issue.get("file", "")
+                            },
+                            "region": {
+                                "startLine": issue.get("line", 1),
+                            },
+                        }
+                    }
+                ],
+            }
+            results.append(result)
+
+        return results
+
+    def _severity_to_sarif_level(self, severity: str) -> str:
+        """Convert VibeGuard severity to SARIF level."""
+        mapping = {
+            "critical": "error",
+            "error": "error",
+            "warning": "warning",
+            "info": "note",
+        }
+        return mapping.get(severity, "warning")