Leclerc was driving before Ferrari, including several Monza bikes this year, but predicted that his first test as an official racing driver would be "emotional" and "special" experience.
He started the fastest time in the first four days on Wednesday, which will continue for another five hours until 18:00 (local time).
Leclerc climbed to the summit of the second hour with a wedge of 1: 36,938, then dropped another two hundred sows later, remaining ten times slower than Sebastian Vettel's time on Tuesday.
The 21-year-old driver was even faster at noon sooner and scored 1: 36,559, almost three-tenths below the best of Vettel, despite unknown weight and configuration conditions.
Like Leclerc, Pierre Gasla is testing one of three current F1 teams when he was at the Red Bull steering wheel he will compete with in 2019.
Gasly, who last piloted Red Bull in tests in August 2017, set the second best time when he was better than Leclerc after four o'clock.
Lance Stroll, who has not yet been confirmed but was expecting a racing point for Racing Point Force India, appeared in the team after first appearing pink on Tuesday.
Walk the third fastest time, improve as the first two, after noon and stay 0.070 seconds behind Gasla.
Valtteri Bottas continued on the second day of testing at the Mercedes and was the fourth fastest in the first four hours.
Daniil Kvyat took the wheel for the first time behind the wheel of Toro Rosso after he was released after the US Grand Prix in 2017. Russia finished the first five, 2.3 seconds behind Leclerc.
His compatriot Artem Markelov was sixth with Renault, while Louis Deletraz debuted in F1 with Haas seventh, with the best time of 1: 40,153, recorded at 2 o'clock.
It left two tenths of new McLaren, Carlo Sainze, who finished the first kilometer with the Woking team.
Antonio Giovinazzi replaced Kimi Raikkonen in Sauber and was the ninth fastest in front of Robert Kubica, who did not set a representative time in the morning and left behind his 2019 co-player George Russell for the rest of the day,
F1 – Abu Dhabi Test – Wednesday – Morning Session
|1||Charles Leclerc||Ferrari SF71H||1 & lt; / RTI & gt; 36.559||54|
|2||Pierre Gasly||Red Bull RB14||1 & 37.976||63|
|3||Lance Stroll||Force India VJM11||1 & 38.044||47|
|4||Valtteri Bottas||Mercedes F1 W09 EQ performance +||1 & 38.590||78|
|5||Daniil Kvyat||Toro Rosso STR13||1 & 38.862||52|
|6||Artem Markelov||Renault R.S.18||1 & 39.240||47|
|7||Louis Deletraz||Haas VF-18||1 & lt; / RTI & gt;||51|
|8||Carlos Sainz||McLaren MCL33||1 & lt; / RTI & gt; 40,383||59|
|9||Antonio Giovinazzi||Sauber C37||1 & lt; / RTI & gt; 40,435||41|
|10||Robert Kubica||Williams FW41||1 & amp; 44.208||39|