Reactions of Li+ [(η5‐C5H5)Re(NO)(PPh3)]− with 2‐ and 4‐chloroquinoline or 1‐chloroisoquinoline give the corresponding σ quinolinyl and isoquinolinyl complexes 3, 6, and 8. With 3 and 8 there is further protonation to yield HCl adducts, but additions of KH give the free bases. Treatment of 3 with HBF4⋅OEt2 or H(OEt2)2+ BArf− gives the quinolinium salts [(η5‐C5H5)Re(NO)(PPh3)(C(NH)C(CH)4C(CH)(CH))]+ X− (3‐H+ X−; X−=BF4−/BArf−, 94–98 %). Addition of CF3SO3CH3 to 3, 6, or 8 affords the corresponding N‐methyl quinolinium salts. In the case of [(η5‐C5H5)Re(NO)(PPh3)(C(NCH3)C(CH)4C(CH)(CH))]+ CF3SO3− (3‐CH3+ CF3SO3−), addition of CH3Li gives the dihydroquinolinium complex (SReRC,RReSC)‐[(η5‐C5H5)Re(NO)(PPh3)(C(NCH3)C(CH)4C(CHCH3)(CH2))]+ CF3SO3− ((SReRC,RReSC)‐5+ CF3SO3−, 76 %) in diastereomerically pure form. Crystal structures of 3‐H+ BArf−, 3‐CH3+ CF3SO3−, (SReRC, RReSC)‐5+ Cl−, and 6‐CH3+ CF3SO3− show that the quinolinium ligands adopt Re⋅⋅⋅C conformations that maximize overlap of their acceptor orbitals with the rhenium fragment HOMO, minimize steric interactions with the bulky PPh3 ligand, and promote various π interactions. NMR experiments establish the Brønsted basicity order 3>8>6, with Ka(BH+) values >10 orders of magnitude greater than the parent heterocycles, although they remain less active nucleophilic catalysts in the reactions tested. DFT calculations provide additional insights regarding Re⋅⋅⋅C bonding and conformations, basicities, and the stereochemistry of CH3Li addition.