Answer:
No
Step-by-step explanation:
While it is usually convention that words, especially nouns, that end in "o" are considered masculine and words that end in "a" are feminine, it is not always the case.
Here is a counterexample:
hand - English
la mano - Spanish
As you can see, "hand" has a feminine article ("la") in Spanish, despite ending in "o".
Hope this helps!