In Ontario, Canada, posting a “No Trespassing” sign is a legal way to indicate that unauthorized entry onto your property is prohibited. The framework for this falls primarily under the Trespass to Property Act, RSO 1990, c T.21, which governs trespassing laws in the province. Below is a clear explanation of how “No Trespassing” signs work in Ontario, their legal implications, and practical considerations:

1. Purpose of a No Trespassing Sign
A “No Trespassing” sign serves as a formal notice to others that they are not permitted to enter or remain on your property without permission. It provides evidence that you, as the property owner or occupier, have explicitly communicated your intent to restrict access.
2. Legal Basis: Trespass to Property Act
The Trespass to Property Act outlines the rules for trespassing in Ontario. Key points relevant to “No Trespassing” signs include:
- Trespass Offence: Under Section 2(1) of the Act, a person commits trespass if they:
- Enter a property where entry is prohibited (e.g., where a sign is posted).
- Engage in an activity on the property that is prohibited.
- Fail to leave the property when directed by the occupier or their agent.
- Notice Requirement: The Act allows property owners to give notice that entry is prohibited. This can be done:
- In writing (e.g., a “No Trespassing” sign).
- Orally (e.g., verbally telling someone to leave).
- By implied notice (e.g., physical barriers like fences or gates that clearly indicate restricted access).
A “No Trespassing” sign is a common and effective way to provide written notice.
3. Requirements for No Trespassing Signs
While the Trespass to Property Act does not prescribe specific wording or design for signs, there are practical and legal considerations to ensure their effectiveness:
- Clarity: The sign should clearly state that unauthorized entry is prohibited. Common wording includes:
- “No Trespassing”
- “Private Property – No Entry”
- “Trespassers Will Be Prosecuted”
- Visibility: Signs should be placed in locations where they are easily seen by potential trespassers, such as:
- Entry points (e.g., gates, driveways, or pathways).
- Perimeter boundaries of the property.
- Near areas where trespassing is a concern (e.g., near a private dock or forested area).
- Durability: Signs should be weather-resistant and legible to ensure they remain effective over time.
- Size and Placement: While there’s no mandated size, signs should be large enough to be readable from a reasonable distance. For large properties, multiple signs may be needed to ensure adequate notice.
- Specificity (if needed): If certain activities are prohibited (e.g., hunting, fishing, or parking), the sign should specify this. For example, “No Hunting or Fishing” or “No Parking Without Permission.”
4. Legal Effect of a No Trespassing Sign
- Prohibited Entry: A properly displayed sign indicates that entry without permission is a trespass offence under the Act. This applies to private property, such as homes, cottages, farms, or businesses.
- Evidence in Court: If a trespasser is charged, the sign serves as evidence that the property owner or occupier provided clear notice that entry was prohibited.
- Limited Exceptions: Certain individuals may have a legal right to enter despite a sign, such as:
- Emergency services (e.g., police, firefighters, or paramedics acting in their duties).
- Utility workers or government officials with legal authority (e.g., for inspections or maintenance).
- Implied invitation: If the property is open to the public (e.g., a store during business hours), a sign may not apply unless specific areas are restricted.
5. Enforcement
If someone trespasses on your property despite a “No Trespassing” sign:
- Request to Leave: You can ask the trespasser to leave immediately. If they refuse, they are committing an offence under the Act.
- Contact Authorities: If the trespasser does not leave or if you feel unsafe, you can contact the police. Trespassing is a provincial offence, and police have the authority to:
- Issue a warning.
- Issue a Provincial Offences Notice (ticket) with a fine (typically up to $65 for a first offence, though fines can be higher in some cases).
- Arrest the trespasser in certain circumstances (e.g., if they are causing damage or refusing to leave).
- Civil Action: If trespassing causes damage (e.g., to property or crops), you may pursue a civil lawsuit for damages in addition to any criminal or administrative penalties.
6. Penalties for Trespassing
Under the Trespass to Property Act:
- Trespassing is a provincial offence, not a criminal offence (unless it involves additional crimes like vandalism or assault).
- Fines for a first offence are typically up to $65, but courts can impose higher fines (up to $2,000 in some cases) or other penalties for repeat or serious offences.
- If the trespasser causes damage, they may face additional liability for restitution.
7. Special Considerations
- Rural or Large Properties: For farms, cottages, or large parcels of land, it’s important to place signs at regular intervals along boundaries, especially where access is likely (e.g., trails or roads). Courts may consider whether notice was reasonably communicated.
- Public vs. Private Property: If your property borders public land (e.g., a park or lake), signs are especially important to clarify boundaries.
- Posting on Behalf of Others: If you’re not the property owner (e.g., a tenant or property manager), you must have the owner’s authority to post signs or enforce trespass laws.
- Color-Coded Notices: In some cases, property owners use colored markings (e.g., purple paint) to indicate no trespassing, as permitted in some jurisdictions. However, Ontario’s Trespass to Property Act does not explicitly recognize paint markings, so written signs are the safest option.
8. Practical Tips
- Document Trespassing Incidents: Take photos or videos of trespassers (if safe to do so) and note dates, times, and details to support any legal action.
- Maintain Signs: Regularly check that signs are visible, intact, and not faded.
- Consider Additional Measures: Fences, gates, or security cameras can reinforce the message that entry is restricted.
- Know Your Boundaries: Ensure you know the exact boundaries of your property to avoid disputes with neighbors or trespassers.
9. Limitations
- A “No Trespassing” sign does not grant you the right to use force to remove someone unless they pose an immediate threat (self-defense laws apply).
- Signs alone may not deter determined trespassers, so be prepared to involve law enforcement if needed.
- If the property is part of a shared space (e.g., a condominium or easement), consult with other stakeholders before posting signs, as restrictions may apply.
Conclusion
In Ontario, a “No Trespassing” sign is a legally recognized way to prohibit unauthorized entry under the Trespass to Property Act. To be effective, signs must be clear, visible, and strategically placed. If a trespass occurs, you can ask the person to leave, contact police, or pursue legal remedies for damages. For specific situations (e.g., large rural properties or commercial spaces), consider consulting a lawyer to ensure your signs and enforcement approach comply with Ontario law.