McLaughlin's victory at Mid-Ohio sealed the sixth win in nine races for Team Penske who continue to dominate the IndyCar campaign.
Chip Ganassi Racing's Alex Palou finished the race in second, while McLaughling's teammate, Will Power, produced the drive of his life to also finish on the podium.
With Kyle Kirkwood going off the track on lap 30, race control threw caution which allowed McLaughlin to maintain his lead. From there, the second-year driver was able to mount a solid defence against Palou to win his second career race.
"It was tough," said the 29-year-old Kiwi. "You were thinking about the fuel. I had driveability off the restarts to get ahead. I had a great car.
"I really wanted to get a win with mom and dad here. To have mom and dad here is pretty special."
Sweden's Marcus Ericsson, who leads the driver standings, finished the race in sixth and saw his points advantage over Power shrink from 27 to just 20.
Mexico's Pato O'Ward, who started on pole position, jumped into an early lead while his teammate Felix Rosenqvist saw his race end early due to a mechanical failure.
O'Ward complained about the loss of power as he pitted on lap 30 and returned to track in third. He then faded down the standings before dropping out altogether.
The closest Palou came to overtaking the eventual winner was on a lap-40 restart, but the Spaniard simply couldn't pull ahead as McLaughlin held on for top spot.
The race also featured controversy between Andretti Autosport teammates Alexander Rossi and Romain Grosjean, as the duo battled for position on lap 60.
Contact between the pair knocked them off course, with Rossi going on to finish 19th while the former F1 man ended the race in 21st.
After the race, the Frenchman made a short comment, saying: "He's an absolute idiot. Sorry."