The Col de Porte (elevation 1,326 m (4,350 ft)) is a mountain pass situated in the Chartreuse Mountains in the Isère department of France, between Le Sappey-en-Chartreuse to the south and Saint-Pierre-de-Chartreuse to the north. It sits on the D512 between Grenoble and Chambéry, and prior to 1998 was often crossed in conjunction with the Col du Cucheron and the Col du Granier.

To the east is Chamechaude, the highest summit in the Chartreuse Massif. There is a small ski resort situated near the col.

The Col de Porte is regularly used in the Critérium du Dauphiné. In the sixth stage of the 1977 Critérium, Bernard Hinault fell on the descent from the Col de Porte leading to Grenoble when he was alone in the lead, 1'40" ahead of his competitors. Despite the fall, he won the stage at Bastille in Grenoble ahead of Lucien Van Impe and Bernard Thévenet.

From Grenoble, to the south, the climb via the D512 is 17.7 km (11.0 mi) long, gaining 1,116 m (3,661 ft) in altitude, at an average gradient of 6.3%, with the steepest section being at 10%. 2.5 km (1.6 mi) from the summit, it passes the Col de Palaquit (1,154 m (3,786 ft)).

The pass was first included in the Tour de France in 1907, after which it was used in the next three tours, and then not again until 1947.

Since 1947, the passages which have been categorized have been:

Year	Stage	Category	Start	Finish	Leader at the summit
2020	16	1	La Tour-du-Pin	Villard-de-Lans	Pierre Rolland (FRA)
1998	16	1	Vizille	Albertville	Stéphane Heulot (FRA)
1989	19	1	Villard-de-Lans	Aix-les-Bains	Pedro Delgado (ESP)
1978	17	1	Grenoble	Morzine	André Romero (FRA)
1971	10	1	Saint-Etienne	Grenoble	Luis Ocaña (ESP)
1970	12	1	Thonon-les-Bains	Grenoble	Eddy Merckx (BEL)
1968	18	1	Saint-Etienne	Grenoble	Roger Pingeon (FRA)
1965	17	1	Briançon	Aix-les-Bains	Julio Jiménez (ESP)
1963	15	1	Saint-Etienne	Grenoble	Federico Bahamontes (ESP)
1962	19	1	Briançon	Aix-les-Bains	Raymond Poulidor (FRA)
1961	9	2	Saint-Etienne	Grenoble	Charly Gaul (LUX)
1958	21	1	Briançon	Aix-les-Bains	Charly Gaul (LUX)
1951	21	1	Briançon	Aix-les-Bains	Bernard Gauthier (FRA)
1948	14	2	Briançon	Aix-les-Bains	Gino Bartali (ITA)