wrongful - unlawfully violating the rights of others; "wrongful death"
In Canadian law, absent a written contract which addresses how to end the employment relationship, the law implies into the employment relationship a term that it will not be ended without "reasonable notice" of its termination. The length of reasonable notice depends on a number of factors, best described by the Ontario Court in the 1960 decision of Bardal v. Globe & Mail.
There could be no catalogue laid down as to what was reasonable notice in particular classes of cases. The reasonableness of the notice must be decided with reference to each particular case, having regard to the character of the employment, the length of the service of the servant, the age of the servant and the availability of similar employment, having regard to the experience, training and qualifications of the servant.
Thus (in Canadian law), a dismissal is not wrongful unless the employer alleges cause for dismissal without proper grounds. Most dismissals are not "wrongful". Rather, the question is "Did the employer provide proper notice of the termination of employment?" If the employer did not provide proper notice of the termination, then a breach of contract occurred. Damages will be awarded in an amount that compensates the employee for the wages and benefits the employee would have earned during the implied notice period (usually measured in a number of months), less the money the fired employee earned if a new job is found during the implied notice period (known as "mitigation").
In Canadian employment law, it has
long been the rule that reinstatement is not a remedy available to
either the employer or the employee - damages must be paid instead.

Wrongful
dismissal, also called wrongful termination or wrongful
discharge, is an idiom and legal phrase, describing a situation in which
an employee's contract of employment has been terminated by the employer in
circumstances where the termination breaches one or more terms of the
contract of employment, or a statute provision in employment law.