Under the current understanding of the Standard Model, there are only three possible charge magnitudes for fundamental particles: $e$ (for leptons such as electrons), $\frac23 e$, and $\frac13 e$ (for various types of quarks). So if we restrict ourselves to fundamental particles, the answer is that no more highly charged particles exist.

However, baryons are composite particles formed from three quarks, and if all three have charge $\frac23 e$, then the resulting particle will have net charge $2e$. This would be the highest charge possible for a conventional baryon; and several such baryons have been observed (such as the $\Delta ^{++}$ noted in JEB’s answer.)

Exotic baryons such as pentaquarks could, I think, in principle even have a charge of $3e$ (for example, a pentaquark with valence quarks $uuuu\bar{d}$.) But only a couple of pentaquark baryons have been detected to date, and both of them have a charge of magnitude $e$ only.

Under the current understanding of the Standard Model, there are only three possible charge magnitudes for fundamental particles: $e$ (for leptons such as electrons), $\frac23 e$, and $\frac13 e$ (for various types of quarks). There are also uncharged fundamental particles (neutrinos). So if we restrict ourselves to fundamental particles, the answer is that no more highly charged particles exist.

However, baryons are composite particles formed from three quarks, and if all three have charge $\frac23 e$, then the resulting particle will have net charge $2e$. This would be the highest charge possible for a conventional baryon; and several such baryons have been observed (such as the $\Delta ^{++}$ noted in JEB’s answer.)

Exotic baryons such as pentaquarks could, I think, in principle even have a charge of $3e$ (for example, a pentaquark with valence quarks $uuuu\bar{d}$.) But only a couple of pentaquark baryons have been detected to date, and both of them have a charge of magnitude $e$ only.

Under the current understanding of the Standard Model, there are only three possible charge magnitudes for fundamental particles: $e$ (for leptons such as electrons), $\frac23 e$, and $\frac13 e$ (for various types of quarks). So if we restrict ourselves to fundamental particles, the answer is that no more highly charged particles exist.

However, baryons are composite particles formed from three quarks, and if all three have charge $\frac23 e$, then the resulting particle will have net charge $2e$. This would be the highest charge possible for a conventional baryon; and several such baryons have been observed (such as the $\Delta ^{++}$ noted in another answer).

Exotic baryons such as pentaquarks could, I think, in principle have even have a charge of $3e$ (for example, a pentaquark with valence quarks $uuuu\bar{d}$.) But only a couple of pentaquark baryons have been detected to date, and both of them have a charge of magnitude $e$ only.

Under the current understanding of the Standard Model, there are only three possible charge magnitudes for fundamental particles: $e$ (for leptons such as electrons), $\frac23 e$, and $\frac13 e$ (for various types of quarks). So if we restrict ourselves to fundamental particles, the answer is that no more highly charged particles exist.

However, baryons are composite particles formed from three quarks, and if all three have charge $\frac23 e$, then the resulting particle will have net charge $2e$. This would be the highest charge possible for a conventional baryon; and several such baryons have been observed (such as the $\Delta ^{++}$ noted in JEB’s answer.)

Exotic baryons such as pentaquarks could, I think, in principle even have a charge of $3e$ (for example, a pentaquark with valence quarks $uuuu\bar{d}$.) But only a couple of pentaquark baryons have been detected to date, and both of them have a charge of magnitude $e$ only.