In Manusmriti, Brahma and Narayana are mentioned. But i didn't found mention of Lord Shiva. Is he also mentioned there?
This answer 1 prooves that Rudra and Shiva are same. Hence I am quoting mention of Lord Rudra in Manu Smriti
They call the Fathers “Vasus;” the grandfathers they call “Rudras,” and the great-grandfathers they call “ādityas” such is the ancient text.(Manu 3.284)
The Rudras, Ādityas and the Maruts, along with the Great Sages, have performed this penance, for deliverance from all evils.(Manu 11.221)
But he who has committed many sins becomes pure if he recites during a month the four verses addressed to Soma and Rudra and three verses begenning 'Aryaman, Varuna and Mitra' while he bathes in a river. (Manu 9.255)