The pair's fractured relationship is expected to determine whether the Belgian striker plays any part in the club's final three matches of the season.
Lukaku's agent Federico Pastorello confirmed the reunion to DAZN Belgium, striking a conciliatory tone about a situation that had grown increasingly tense over the preceding weeks.
"I know both of them very well and they both live football with great passion. That was not the right moment for a meeting a couple of weeks ago, but they will see each other today."
He was equally direct about the forward's return to full training.
"Lukaku is back in Naples as planned. He will start working with the squad now that he is in shape. Then obviously it will be up to manager Conte to decide what to do with Romelu."
The background to the reunion is complicated. Lukaku suffered a severe muscle injury in pre-season that kept him sidelined for the first two months of the campaign.
He returned in November and contributed before picking up a further setback in February. During the most recent international break in March, he refused to return to Naples for training, choosing to remain in Antwerp to undergo individual sessions. The club fined him and froze him out of the squad.
He made a brief visit to Naples in late April to meet sporting director Giovanni Manna, but did not see Conte or his teammates on that occasion — a point Conte addressed with visible frustration after the win over Cremonese.
"My door is always open, but no one knocked. And this makes me sad."
Napoli need points from their remaining fixtures against Bologna, Lazio and Fiorentina to secure second place in Serie A and guarantee Champions League qualification.
With Rasmus Hojlund confirmed as a permanent signing regardless of that outcome, Conte's squad depth in attack is sufficient — but the manager's decision on whether to reintegrate Lukaku before the campaign ends will carry significant implications for the Belgian's future at the club beyond this season. His contract runs until 2027 at a salary of around €8.5 million per year.