Spanish is an official language in 20 sovereign states and one dependent entity, totaling around 423 million speakers.
Official and national language
Sovereign states where Spanish is a de jure official language.
Country
Population (2011)[1]
Spain[2]
46,754,784
Colombia[3]
44,725,543
Peru[4]
29,248,943
Venezuela[5]
27,635,743
Ecuador[6]
15,007,343
Guatemala[7]
13,824,463
Cuba[8]
11,087,330
Bolivia[9]
10,118,683
Honduras[10]
8,143,564
Paraguay[11]
6,459,058
El Salvador[12]
6,071,774
Costa Rica[13]
4,576,562
Panama[14]
3,460,462
Equatorial Guinea[15]
668,225
Dependent entities where Spanish is a de jure official language.
Country
Population (2011)[1]
Puerto Ricoa [16]
3,989,133

De facto official and national language
Sovereign states where Spanish is a de facto official language. That is, it is the main or only language of communication of the vast majority of the population; official documents are written chiefly or solely in that language; and it is spoken and taught in schools; yet, it is not established by legislation as an official language.
Country
Population (2011)[1]
Mexico[17]
113,724,226
Argentina[18]
41,769,726
Chile[19]
16,888,760
Dominican Republic[20]
9,956,648
Nicaragua[21]
5,666,301
Uruguay[22]
3,308,535

SOURCE: http://en.wikipedia.org/wiki/List_of_countries_where_Spanish_is_an_official_language