The present disclosure describes antibodies which bind human and Macaca fascicularis CEACAM5 proteins, as well as isolated nucleic acids, vectors and host cells comprising a sequence encoding said antibodies. The disclosure also provides immunoconjugates comprising said antibodies conjugated or linked to a growth-inhibitory agent, and to pharmaceutical compositions comprising antibodies, or immunoconjugates of the disclosure . The antibodies or immunoconjugates of the disclosure are used for the treatment of cancer or for diagnostic purposes.