The Lionesses are flying high on home soil having beat Austria in the tournament opener before securing a historic 8-0 win over Norway.
Sarina Wiegman's side scored six goals in a rampant first-half display that included a double from Beth Mead and Ellen White.
The second half was slightly more subdued but there was enough time for Mead grab a third for her hat-trick.
England, who are already into the quarter-finals, are three points clear in Group A and only need a draw to top the standings.
England v Northern Ireland: talkSPORT commentary
This Group A clash will take place on Friday, July 15.
talkSPORT will have live coverage from Southampton's St. Mary's Stadium with kick-off scheduled for 8pm.
Adrian Durham will be your presenter while commentary will come from Sam Matterface and former England striker Lianne Sanderson.
To tune in to talkSPORT or talkSPORT 2 through the website, click HERE for the live stream. You can also listen via the talkSPORT app, on DAB digital radio, through your smart speaker and on 1089 or 1053 AM.
England v Northern Ireland: Team news
England
Goalkeepers: Mary Earps (Manchester United), Hannah Hampton (Aston Villa), Ellie Roebuck (Manchester City)
Defenders: Millie Bright (Chelsea), Lucy Bronze (unattached), Jess Carter (Chelsea), Rachel Daly (Houston Dash), Alex Greenwood (Manchester City), Demi Stokes (Manchester City), Lotte Wubben-Moy (Arsenal)
Midfielders: Fran Kirby (Chelsea), Jill Scott (unattached), Ella Toone (Manchester United), Georgia Stanway (Bayern Munich), Keira Walsh (Manchester City), Leah Williamson (Arsenal)
Forwards: Beth England (Chelsea), Lauren Hemp (Manchester City), Chloe Kelly (Manchester City), Beth Mead (Arsenal), Nikita Parris (Arsenal), Alessia Russo (Manchester United), Ellen White (Manchester City)
Northern Ireland
Goalkeepers: Jackie Burns (BK Hacken), Becky Flaherty (Brighouse Town), Shannon Turner (Wolverhampton Wanderers Women)
Defenders: Kelsie Burrows (Cliftonville Ladies), Rebecca Holloway (Racing Louisville), Ashley Hutton (Linfield Ladies), Abbie Magee (Cliftonville Ladies), Sarah McFadden (Durham Women), Rebecca McKenna (Lewes Women), Julie Nelson (Crusaders Strikers), Laura Rafferty (Southampton Women), Demi Vance (Rangers Women)
Midfielders: Nadene Caldwell (Glentoran Women), Joely Andrews (Glentoran Women), Chloe McCarron (Glentoran Women), Marissa Callaghan (Cliftonville Ladies), Louise McDaniel (Cliftonville Ladies), Rachel Furness (Liverpool Women)
Forwards: Simone Magill (unattached), Caitlin McGuinness (Cliftonville Ladies), Kirsty McGuinness (Cliftonville Ladies), Lauren Wade (Glentoran Women), Emily Wilson (Crusaders Strikers)
England v Northern Ireland: What has been said?
"We just want to do well," Wiegman told talkSPORT. "We have a dream but we take it match by match and next match we want to win.
"We have nothing now, we still have nothing.
"It's really nice that we have this good game and we're only talking about football and being in the now.
"We hope we in every next game."
Sports Bar host Jason Cundy also urged England men's captain Harry Kane to learn from White in the art of winning penalties.
"It was a blatant dive from Ellen White, I don't know how we got away with it," a chuffed Cundy said.
"If that was Harry Kane I'd be saying well done, getting England off to a good start, making the referee give a decision in your favour to get yourself off and running.
"It's good to see the dark arts are alive and well in women's football.
"I've been critical of England's men team not doing it enough at tournament level, good to see the girls are doing it to get themselves off to a good start!
"And it's good to see the women are capable of doing something similar."
He continued: "When I say she went down and she dived, it's not a criticism.
"It's a compliment from me saying in those situations the first goal often is so important.
"That shows to me a smart, clever, centre-forward player and as I've said, if Harry Kane does that at the World Cup in November I'll be here saying exactly the same thing.
"You're looking to gain those little advantages that we know at the highest level can be so crucial."