diff --git a/backend/app/models/__init__.py b/backend/app/models/__init__.py
index 96e2dc3..8e95c5b 100644
--- a/backend/app/models/__init__.py
+++ b/backend/app/models/__init__.py
@@ -2,5 +2,8 @@ from app.models.user import User
 from app.models.session import Session
 from app.models.world import World
 from app.models.asset import Asset
+from app.models.report import Report
+from app.models.moderation_action import ModerationAction
+from app.models.appeal import Appeal
 
-__all__ = ["User", "Session", "World", "Asset"]
+__all__ = ["User", "Session", "World", "Asset", "Report", "ModerationAction", "Appeal"]
diff --git a/backend/app/models/appeal.py b/backend/app/models/appeal.py
new file mode 100644
index 0000000..ad8bda4
--- /dev/null
+++ b/backend/app/models/appeal.py
@@ -0,0 +1,74 @@
+"""Appeal model for moderation actions."""
+
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy import (
+    Column,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+    DateTime,
+    CheckConstraint,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class Appeal(Base):
+    __tablename__ = "appeals"
+
+    # Status values
+    APPEAL_STATUS = Enum(
+        "pending", "approved", "rejected",
+        name="appeal_status",
+        create_type=False,
+    )
+
+    id = Column(Integer, primary_key=True, index=True)
+    moderation_action_id = Column(
+        Integer,
+        ForeignKey("moderation_actions.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    reason = Column(Text, nullable=False)
+    status = Column(
+        APPEAL_STATUS,
+        nullable=False,
+        default=APPEAL_STATUS.PENDING,
+    )
+    reviewed_by = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    reviewed_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        nullable=False,
+    )
+
+    # Relationships
+    moderation_action = relationship("ModerationAction", back_populates="appeals")
+    reviewer = relationship(
+        "User",
+        foreign_keys=[reviewed_by],
+        backref="reviewed_appeals",
+    )
+
+    __table_args__ = (
+        CheckConstraint(
+            "status IN ('pending', 'approved', 'rejected')",
+            name="check_appeal_status",
+        ),
+    )
diff --git a/backend/app/models/moderation_action.py b/backend/app/models/moderation_action.py
new file mode 100644
index 0000000..55472d2
--- /dev/null
+++ b/backend/app/models/moderation_action.py
@@ -0,0 +1,113 @@
+"""Moderation action model."""
+
+from datetime import datetime
+from enum import Enum as PyEnum
+from typing import Optional
+
+from sqlalchemy import (
+    Column,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+    DateTime,
+    func,
+)
+from sqlalchemy.dialects.postgresql import TIMESTAMPTZ
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+class TargetType(str, PyEnum):
+    """Type of entity being reported or moderated."""
+    USER = "user"
+    WORLD = "world"
+    ASSET = "asset"
+    CHAT_MESSAGE = "chat_message"
+
+
+class ReasonCategory(str, PyEnum):
+    """Category of report reason."""
+    HARASSMENT = "harassment"
+    HATE_SPEECH = "hate_speech"
+    SEXUAL_CONTENT = "sexual_content"
+    VIOLENCE = "violence"
+    SPAM = "spam"
+    SELF_HARM = "self_harm"
+    OTHER = "other"
+
+
+class ReportStatus(str, PyEnum):
+    """Status of a report."""
+    OPEN = "open"
+    IN_REVIEW = "in_review"
+    RESOLVED = "resolved"
+    DISMISSED = "dismissed"
+
+
+class Resolution(str, PyEnum):
+    """Resolution outcome of a report."""
+    ACTION_TAKEN = "action_taken"
+    NO_ACTION = "no_action"
+
+
+class ModerationActionType(str, PyEnum):
+    """Type of moderation action."""
+    WARN = "warn"
+    SUSPEND = "suspend"
+    BAN = "ban"
+    RESTRICT = "restrict"
+    REMOVE = "remove"
+    RESTORE = "restore"
+
+
+class ModerationAction(Base):
+    __tablename__ = "moderation_actions"
+
+    id = Column(Integer, primary_key=True, index=True)
+    moderator_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    target_user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    target_type = Column(
+        Enum(TargetType, name="target_type_enum", create_type=False),
+        nullable=False,
+    )
+    target_id = Column(String(64), nullable=False)
+    action = Column(
+        Enum(ModerationActionType, name="moderation_action_type_enum", create_type=False),
+        nullable=False,
+    )
+    reason = Column(Text, nullable=True)
+    report_id = Column(
+        Integer,
+        ForeignKey("reports.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    expires_at = Column(TIMESTAMPTZ, nullable=True)
+    revoked_at = Column(TIMESTAMPTZ, nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+    )
+
+    # Relationships
+    moderator = relationship(
+        "User",
+        foreign_keys=[moderator_id],
+        back_populates="moderation_actions_given",
+    )
+    target_user = relationship(
+        "User",
+        foreign_keys=[target_user_id],
+        back_populates="moderation_actions_received",
+    )
+    report = relationship("Report", back_populates="moderation_actions")
diff --git a/backend/app/models/report.py b/backend/app/models/report.py
new file mode 100644
index 0000000..8420d4a
--- /dev/null
+++ b/backend/app/models/report.py
@@ -0,0 +1,145 @@
+"""Report model for user-generated moderation reports."""
+
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy import (
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+)
+from sqlalchemy.dialects.postgresql import TIMESTAMPTZ
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+class ReportStatus:
+    """Valid statuses for a Report."""
+
+    OPEN = "open"
+    IN_REVIEW = "in_review"
+    RESOLVED = "resolved"
+    DISMISSED = "dismissed"
+
+
+class Resolution:
+    """Possible resolution outcomes for a Report."""
+
+    ACTION_TAKEN = "action_taken"
+    NO_ACTION = "no_action"
+
+
+class TargetType:
+    """Types of entities that can be reported."""
+
+    USER = "user"
+    WORLD = "world"
+    ASSET = "asset"
+    CHAT_MESSAGE = "chat_message"
+
+
+class ReasonCategory:
+    """Categories for why something was reported."""
+
+    HARASSMENT = "harassment"
+    HATE_SPEECH = "hate_speech"
+    SEXUAL_CONTENT = "sexual_content"
+    VIOLENCE = "violence"
+    SPAM = "spam"
+    SELF_HARM = "self_harm"
+    OTHER = "other"
+
+
+class Report(Base):
+    __tablename__ = "reports"
+
+    id = Column(Integer, primary_key=True, index=True)
+    reporter_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    target_type = Column(
+        Enum(
+            TargetType.USER,
+            TargetType.WORLD,
+            TargetType.ASSET,
+            TargetType.CHAT_MESSAGE,
+            name="target_type",
+            create_type=False,
+        ),
+        nullable=False,
+    )
+    target_id = Column(String(64), nullable=False)
+    reason_category = Column(
+        Enum(
+            ReasonCategory.HARASSMENT,
+            ReasonCategory.HATE_SPEECH,
+            ReasonCategory.SEXUAL_CONTENT,
+            ReasonCategory.VIOLENCE,
+            ReasonCategory.SPAM,
+            ReasonCategory.SELF_HARM,
+            ReasonCategory.OTHER,
+            name="reason_category",
+            create_type=False,
+        ),
+        nullable=False,
+    )
+    details = Column(Text, nullable=True)
+    status = Column(
+        Enum(
+            ReportStatus.OPEN,
+            ReportStatus.IN_REVIEW,
+            ReportStatus.RESOLVED,
+            ReportStatus.DISMISSED,
+            name="report_status",
+            create_type=False,
+        ),
+        nullable=False,
+        default=ReportStatus.OPEN,
+    )
+    resolved_by = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    resolution = Column(
+        Enum(
+            Resolution.ACTION_TAKEN,
+            Resolution.NO_ACTION,
+            name="resolution",
+            create_type=False,
+        ),
+        nullable=True,
+    )
+    created_at = Column(
+        TIMESTAMPTZ,
+        nullable=False,
+        server_default=sa.func.now(),
+    )
+    updated_at = Column(
+        TIMESTAMPTZ,
+        nullable=False,
+        server_default=sa.func.now(),
+        onupdate=sa.func.now(),
+    )
+    resolved_at = Column(TIMESTAMPTZ, nullable=True)
+
+    # Relationships
+    reporter = relationship("User", foreign_keys=[reporter_id])
+    resolver = relationship("User", foreign_keys=[resolved_by])
+    moderation_actions = relationship(
+        "ModerationAction",
+        back_populates="report",
+        cascade="all, delete-orphan",
+    )
+    appeals = relationship(
+        "Appeal",
+        back_populates="report",
+        cascade="all, delete-orphan",
+    )