Meghan said they were honoured to make their first visit to Nigeria and urged the students not to suffer in silence.
Britain's Prince Harry and his wife Meghan on Friday attended an inaugural mental health summit at a school run by a local non-profit linked to their foundation in Nigeria's capital Abuja, as they kicked off their first trip to Africa's most populous nation.
The couple were invited to Nigeria by the chief of defence staff.
At Lightway Academy, run by a non-profit supported by their Archewell Foundation, Harry and Meghan were received with wild cheers and serenaded by dancers and singers.
And it was time to talk about mental health, which carries deep-rooted stigma in conservative Nigeria.
"Too many people don't want to talk about it 'cause it's invisible. It's something in our mind that we can't see. It's not like a broken leg, it's not like a broken wrist," said Harry.
"Every single person in this room, the youngest, the oldest, every single person has mental health. So therefore, you have to look after yourself to be able to look after other people," Harry said, adding that "there is no shame" to acknowledge it.
Meghan said they were honoured to make their first visit to Nigeria and urged the students not to suffer in silence.
"Just make sure that you are taking care of yourselves and that begins with your mental health by really talking about whatever's coming up for you," she said.
The couple also visited a kindergarten class, and when introduced to a five-year-old student, the oldest in the class, Meghan said: "Our son Archie's five. He turned five last week."