Access to 1,3-conjugated enynes with defined stereoselectivity is highly desirable and challenging. Herein, we report a facile synthesis of stereodefined 1,3-conjugated enynes via Ni-catalyzed intermolecular cross-alkylalkynylation of alkynes with unsaturated carbonyl compounds and alkynes or alkynyl silicates. The operational simple protocol proceeds at room temperature and tolerates a wide range of functional groups, providing an attractive alternative to carbonyl-tethered trisubstituted conjugated 1,3-enynes from easily accessible starting materials.