King said Beautrais was "completely misinformed".
"Annette Beautrais has never been to one of my talks, she clearly hasn't been to my website and read any of the references we've had from schools, she clearly doesn't understand that we don't focus on suicide at all at any of our talks," King said.
King said his talks focused on self-esteem and managing the "inner critic".
"Annette has also been a longtime campaigner of the 'Let's keep the S word silent', she has been a long term campaigner of how talking about suicide could be a trigger for some children."
King doesn't feel Beautrais' opposition to his talks is personal, but is reflective of her philosophy towards the issue.
"She's failing to move with the evidence and failing to move with the times. She still thinks all young people should be treated like five-year-olds."
King said he has not spoken to Beautrais about her intervention but South Canterbury DHB chief executive Nigel Trainor had been "fantastic" when he approached him.
"We discussed the work I do and immediately found that our philosophies aligned... and he immediately agreed that we should be working together. They have been nothing but fantastic."
King said he has "no issue" with schools not wanting him to present to their students.
"The bottom line is schools know what's best for their kids. And schools and communities have the right, they have the last right to when it comes to what is presented to their kids.
"It is their job to decide what goes in front of their kids, not Mike King, not Annette Beautrais, not anybody else and I support them 110 per cent."
South Canterbury DHB and Annette Beautrais have been approached for comment.
Trainor confirmed to Fairfax that they had raised concerns about King's talks with the schools.
"Since then we have had discussions with Mike King which have highlighted that our goals are aligned.
"We are working with Mike King and will support his visits."
King had previously berated the government for its failure to include a measurable goal in its draft suicide prevention policy after standing down from New Zealand's suicide-prevention panel in May.
The panel was established to help shape a strategy to reduce suicide over the next 10 years. Its Draft Suicide Prevention Plan was released to the public in March.
But key measures - including a 20 per cent reduction in suicides over 10 years - have been removed from the plan.
Where to get help: If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
Or if you need to talk to someone else:
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (Mon-Fri 1pm to 10pm. Sat-Sun 3pm-10pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.