Rough estimates place the number of Druze:

390,000 in Lebanon,
420,000 in Syria,
75,000 in Palestine,
15,000 in Jordan, and
about 80,000 scattered around the rest of the world, mostly in North America, Australia, and West Africa.

The American Druze Society estimates the number of Druze in the United States at between 15,000 and 20,000.
Pam Rohland  - actadruze

about 15,000 live in northern Syria near Aleppo,
about 20,000 in and around Damascus,
about 25,000 in the districts of Qantana and Qunaytira in southwestern Syria, and about 200,000 in Jabal ad-Duruz.
The Druze Faith, Sami Makarem

About sixty-five thousand Druzes now live in Latin America, especially in Venezuela, Brazil, Argentina, Buenos Aries, and Mexico, with smaller communities in Chile and Colombia. 

There are also about 20 thousand Druzes in Australia, the West Indies and the Philippines, as well as in Africa.

In the United States of America and in Canada, the Druzes are estimated about 35 thousand.

In Europe, there are about 30 thousand Druzes.
Henry Fleihan from the History of the El-Bakaurat Ed-Diryzit, americandruzeheritage.com

Religion and group of people with somewhere between 350,000 (estimate of Western scholars) and 900,000 (figures presented by the Druze) members (LexicOrient estimates that around 600,000 live in the Middle East and nearly 700,000 all over the world), living in Lebanon, Syria, Palestine, and Jordan, often in mountainous regions. There are also important Druze communities abroad, living in Europe and USA.

Middle East
Palestine       80,000 1.1%
Jordan     15,000 0.2%
Lebanon 210,000 5.7%
Syria      300,000 1.7% Tot
605,000 <0.1%
 
Other countries 75,000
Encyclopedia of the Orient

Druze population is nearly one million with

40%-50% living in Syria,
30%-40% in Lebanon,
6%-7% in Palestine, and
1%-2% in Jordan. In the
U.S. there are approximately 20,000 Druzes.

Institute of Druze Studies

Adherents
It is difficult to say with accuracy what the global population of the Druze community is.
In Syria the Druzes number about 260,000 (Makarem 1974, 3);
in Jordan about 3,000 (ibid);
in Israel 89,300 (Europa Publications Ltd. I 1996, 1679);
and in Lebanon 250,000 (Europa Publications Ltd., II 1996).
Small Druze communities also exist in the United States,
Canada,
Brazil,
Mexico,
Argentina and
Australia.

http://www.druzehistoryandculture.com/