Yes, after World War I and the establishment of an independent Czechoslovak state, the total of Bohemia became a part of Czechoslovakia, defying claims of the German speaking inhabitants that regions with German speaking majority should be included in the Republic of German-Austria. Between 1938 and 1945, these border regions were joined to Nazi Germany as the Sudetenland.
It was bordered in the south by Upper and Lower Austria (both in Austria), in the west by Bavaria and in the north by Saxony and Lusatia (all in Germany), in the northeast by Silesia (in Poland), and in the east by Moravia (also part of the Czech Republic). Bohemia's borders were mostly marked by mountain ranges such as the Bohemian Forest, the Ore Mountains, and the Krkonoše, a part of the Sudetes range; the Bohemian-Moravian border roughly follows the Elbe-Danube watershed.
Most of this I generally knew, but was easier to copy and paste from Wikipedia