No. Under Article 10 of Qatar's Property Leasing Law (Law No. 4 of 2008), a landlord cannot increase the rent on an existing or newly concluded lease freely. Any rent increase must comply with the rules, terms, and rates determined by the relevant authority — meaning increases are regulated and cannot simply be imposed at the landlord's discretion.
This protection applies both to leases already in force at the time the law came into effect and to leases concluded after that date. As a tenant, you are not obligated to accept a rent increase that does not follow the prescribed rules and rates.
Practical tip: If your landlord attempts to raise your rent outside the permitted framework, do not simply agree in writing without checking the current permitted rates. You can seek guidance from the Real Estate Lease Registration Office (Article 20) or consult a local legal adviser to confirm whether the proposed increase is lawful.
This is general legal information, not legal advice. For advice on your specific situation, consult a lawyer licensed in Qatar.