[3] After the Bourbon Restoration Mérilhou was placed on the list of magistrates suspended from their functions, and was obliged to leave Paris for several months.

Mérilhou defended the Duclos brothers at the court of assizes in Paris when they were accused of being part of the "black pin" conspiracy.

He also defended Arnold Scheffer, Brissot and Feret, trying to show in each of his pleadings the need to place the institutions of France in harmony with what he thought was the spirit of the Charter of 1814.

[2] On 14 July 1819 Mérilhou won the first case pleaded before a jury, that of Gossuin, editor of the Bibliothèque historique, charged for having criticized the Swiss in the king's guard.

In 1827 he published a book about the life and works of Honoré Gabriel Riqueti, comte de Mirabeau, the great orator and supporter of a constitutional monarchy.

Mérilhou was violently opposed to the ministry of Jules de Polignac and recommended refusal to pay taxes.

[5] On 2 November 1830 Mérilhou replaced Victor de Broglie as Minister of Public Education in the cabinet of Jacques Laffitte.