Thomas More's ideal state in "Utopia" is very similar to the ideal society laid out by Plato in "The Republic."
Both of these two works have the same main thesis. This is that an ideal society can only exist if they people of the society subordinate their own personal desires and rights to the needs of the society as a whole. For More, this means that people will give up private property, which will instead be held in common. For Plato, the rulers and leaders of society will submit to a strictly regimented life because that is what will be best for society.
While this overarching similarity is by far the most important, it is also interesting to note that both thinkers argue for the equal treatment of men and women.
Thomas More's Utopia, first published in Latin in 1516, was perhaps the greatest humanist reform tract of the Renaissance. The work presented a 'perfect society', authoritarian and fictional in its religious, social and political aspects. Indeed, the idea of an ideal state is what Plato's Republic and More's Utopia share, both the works taking a similar stance in their economic systems with regard to the distribution of good and acquisition of wealth.
Both Plato and More were guided by the notion of collective / social good, looking for a state rather abstract and fictional. More's tract with its more pronounced communist / socialist connotations--absence of private ownership and suppression of individuals by the society--looks forward to Karl Marx as it looks back to plato in its general design of a commonwealth.
Both have a generally similar main thesis.