Texas State Highway 123

State Highway 123
State Highway 123
	SH 123; mainline in red, business routes in blue
Route information
	Maintained by TxDOT
Length	71.2 mi (114.6 km)
Existed	by 1933–present
Major junctions
South end	; US 181 / Bus. US 181 / SH 80 in Karnes City
	US 87 in Stockdale; US 90 in Seguin; I-10 in Seguin;
North end	I-35 / Loop 82 in San Marcos
Location
Country	United States
State	Texas
Counties	Karnes, Wilson, Guadalupe, and Hays
Highway system
	Highways in Texas; Interstate; US; State Former; ; Toll; Loops; Spurs; FM/RM; Park; Rec;

State Highway 123 (SH 123) is a north–south state highway in Texas, United States, that connects U.S Route 181 (US 181) in Karnes City with Interstate 35 (I-35) in San Marcos. The route was initially proposed in 1927 and has had minimal changes to its routing since then.