The two leaders will have a bilateral meeting at Twickenham Stadium before Ireland play England in the rugby championship.
They're expected to discuss Brexit, the war in Ukraine and the response of both countries to the refugee crisis it's created.
Taoiseach Micheál Martin told our Political Correspondent Seán Defoe things could get chippy between himself and Boris Johnson during the match
Sean: "Do the diplomatic niceties go out the window once the match starts or how is it going to work for you?"
Taoiseach : "I'd say there will be a few elbows (laughs) He gets excited at these matches, you know"
