Is contract valid that was signed in your name by someone else but with your knowledge?

Yes, a contract signed in your name by someone else can be valid if you have knowledge of and consented to the signing. This situation typically falls under the concept of agency, where one person is authorized to act on behalf of another. However, the specific terms of the contract and the nature of the authorization may affect its enforceability. It's advisable to consult a legal professional for personalized advice.